This is an appeal from a ruling of the Oklahoma Tax Commission (Commission) denying a protest of a proposed assessment of taxpayer, Griffin Television, Inc. and its subsidiaries (Taxpayer). The issues before this Court are whether the assessment is barred by the statute of limitations pursuant to Okla.Stat. tit. 68, § 223(a) (1981), and, if not, whether the gain from the sale of the property in Arkansas should be apportioned between Arkansas and Oklahoma or should be allocated to Arkansas.
I. FACTS
The facts of the protest were stipulated by the parties and adopted by the Administrative Law Judge and the Commission. All the stipulated facts are for the tax periods for the fiscal years 1985 and 1986, the years for which the proposed assessments were issued. Griffin Grocery Company (Griffin Grocery) was a wholly-owned subsidiary of Griffin Television, Inc. Griffin Grocery was composed of two divisions: Griffin Manufacturing and Van Burén Wholesale. For the tax years 1985 and 1986, Taxpayer reported the income and loss of Van Burén Wholesale as allocable 100% to Arkansas. The Commission proposed an additional assessment pursuant to Okla.Stat. tit. 68, § 221 (1981), contending that Griffin Grocery and its two divisions were a unitary business and the income from Van Burén Wholesale should be apportioned between Oklahoma and Arkansas.
Taxpayer’s Oklahoma income tax return for the fiscal year, ending June 30,1.985, was filed with the Commission on September 17, 1985, and the return for the fiscal year, ending June 30,1986, was filed on October 9, 1986. By letters dated July 22, 1988, the Commission notified Taxpayer that it owed additional taxes and interest of $41,410.00 for the fiscal year 1985 and $42,047.00 for the fiscal year 1986. Taxpayer filed a protest within the statutory time.
Taxpayer asserts that an assessment for the purposes of title 68, section 223(a), was never levied, and the limitation period for levying additional taxes has passed. It further asserts that pursuant to title 68, sections 2358(A)(4)(a) and (c) and 2358(A)(5), all of the income from Van Burén Wholesale should be allocated to Arkansas. The Commission counters that the proposed assessment letters were issued within the three-year limitation period and constitute an “assessment” within the meaning of section 223(a). The Commission further argues that the income from Van Burén Wholesale should be apportioned between Oklahoma and Arkansas because the operations of Griffin Grocery and its two divisions were a unitary enterprise.
II. TIME LIMITATION
The applicable limitations period is stated in Section 223(a) of title 68 which provides:
No assessment of any tax levied under the provisions of any state tax law except as provided in the following paragraphs of this Section, shall be made after the expi*590ration of three (3) years from the date the return was required to be filed or the date the return was filed, whichever period expires the later, and no proceedings by tax warrant or in court without the previous assessment for the collection of such tax shall be begun after the expiration of such period.
The proposed assessment was issued pursuant to section 221 of title 68 which provides:
(a) If any taxpayer shall fail to make any report or return as required by any state tax law, the Tax Commission, from any information in its possession or obtainable by it, may determine the correct amount of tax for the taxable period. If a report or return has been filed, the Tax Commission shall examine such report or return and make such audit or investigation as it may deem necessary.... [I]f, in eases where a report or return has been filed, the Tax Commission shall determine that the tax disclosed by such report or return is less than the tax disclosed by its examination, it shall in writing propose the assessment of taxes or additional taxes, as the case may be, and shall mail a copy of the proposed assessment to the taxpayer at his last known address.
While the proposed assessment is not the same as a final assessment for purposes of section 223(a), the issuance of the proposed assessment pursuant to section 221 does toll the three-year limitation period.
In Protest of Pentecost & Hodges, Inc., 186 Okla. 390, 98 P.2d 606 (1940), the taxpayer filed a return on June 15, 1935. On June 4, 1937, the Commission issued a proposed assessment and, on June 25, 1937, issued an amended proposed assessment. At the time the amended proposed assessment had been issued, more than two years had passed since the return was filed and the Commission had not issued an order finalizing the amount of tax. The applicable statute of limitations provided “that the amount of tax levied by any provision of the Act shall be assessed within two years after the return is filed.” Okla.Stat. ch. 66, art. 14, § 12498z1(d) (Supp. 1934).
The taxpayer argued that the statute of limitations barred the assessment. Rejecting the taxpayer’s argument, this Court held that the statute of limitations did not bar the assessment. Pentecost, 98 P.2d at 609. Since the protest time had not run and the Commission had not issued an order finalizing the amount of tax within the two-year statutory period, it follows that the proposed assessment tolled the statute of limitations.
This Court addressed this same issue in In re Woods Corp., 531 P.2d 1381 (Okla.1975). In July of 1969, Woods purchased an airplane in California which was delivered in Montana and flown to and used in Oklahoma. Woods did not pay any sales or use tax on the plane. On May 22, 1970, the Commission issued a proposed assessment for use tax. On June 19, 1970, Woods filed a protest. On November 1, 1973, the Commission entered an order denying the protest.
Woods argued that the statute of limitations had run because the order denying the protest had not been entered within the three-year statute of limitations. This Court held that “the filing of [a] proposed assessment tolls [the] statute of limitations.” Id. at 1386.
As evidenced by these cases, the rule in Oklahoma is that the filing of a proposed assessment tolls the statute of limitations. This rule is in keeping with the Legislature’s intent. The first pronouncement of this rule came in 1940 in Pentecost. In 1965, the Oklahoma Legislature enacted the Oklahoma Tax Code, including section 223 of title 68 which is the statute of limitations for assessing state taxes. In the 1965 enactment, the Legislature chose to leave the rule announced in Pentecost intact.
In Lekan v. P & L Fire Protection Co., 609 P.23 1289, 1292 (Okla.1980), this Court stated:
Legislative familiarity with extant judicial construction of statutes in the process of being amended is presumed. Unless a contrary intent clearly appears or is plainly expressed, the terms of amendatory acts which retain the same, or not substantially dissimilar, portions of provisions formerly in force will be accorded the construction *591identical to that placed upon them by preexisting case law.
Because the Legislature left untouched this Court’s construction of the statute of limitations allowing the proposed assessment to toll its running, this Court must presume that the Legislature acquiesced in this Court’s announcement.
III. ALLOCATION OF INCOME
The Commission argues that the income from the sale of Van Burén Wholesale should be apportioned between Oklahoma and Arkansas pursuant to section 2358(A)(5) of title 68 because Griffin Grocery and its subsidiaries constituted a unitary business. Taxpayer argues that the income should be allocated to Arkansas pursuant to section 2358(A)(4)(a) and (c) because Van Burén Wholesale was a discrete business operation separate from Griffin Grocery and Griffin Manufacturing.
Taxpayer bases its argument, in part, on section 2358(A)(4)(a) which provides: “Income from real and tangible personal property ... and gains or losses from sales of such property, shall be allocated in accordance with the situs of such property.” Because Van Burén Wholesale was a subsidiary of Griffin Grocery, the capital gains realized by Griffin Grocery on the sale of Van Burén Wholesale were gains on the sale of stock which was intangible property. See Allied-Signal, Inc. v. Director, Division of Taxation, — U.S. -, -, 112 S.Ct. 2251, 2259, 119 L.Ed.2d 533 (1992); ASARCO, Inc. v. Idaho State Tax Commission, 458 U.S. 307, 309, 102 S.Ct. 3103, 3105, 73 L.Ed.2d 787 (1982). Because section 2358(A)(4)(a) addresses only real and tangible property, it is not applicable here.
Taxpayer also relies on section 2358(A)(4)(c) which provides: “Net income or loss from a business activity which is not a part of business carried on within or without the state of a unitary character shall be separately allocated to the state in which such activity is conducted.” Section 2358(A)(5) provides that net income or loss derived from a unitary business enterprise shall be taxed under an apportionment formula. In this case if the property is real or tangible personal property or is not derived from a unitary business activity carried on in Oklahoma and Arkansas, Oklahoma will not realize any of the taxes from income resulting from the sale of Van Burén "Wholesale. However, if the income was derived from a unitary business activity carried on in both Oklahoma and Arkansas, the taxes from the sale should be apportioned between Oklahoma and Arkansas.
The Due Process and Commerce Clauses of the United States Constitution generally prohibit a state from taxing income earned outside its borders. Allied-Signal, Inc., — U.S. at -, 112 S.Ct. at 2258. Due process requires that, when a state attempts to tax income earned in another state, it must show that the “taxing power exerted by [it] bears [a] fiscal relation to protection, opportunities and benefits given by the state. The simple but controlling question is whether the state has given anything for which it can ask return.” Wisconsin v. J.C. Penney Co., 311 U.S. 435, 444, 61 S.Ct. 246, 249, 85 L.Ed. 267 (1940). If there is “a ‘minimal connection’ between the interstate activities and the taxing State, and a rational relationship between the income attributed to the State and the intrastate values of the enterprise,” then the due process limitations are satisfied. Mobil Oil Corp. v. Commissioner of Taxes of Vermont, 445 U.S. 425, 436-37, 100 S.Ct. 1223, 1231-32, 63 L.Ed.2d 510 (1980) citing Moorman Mfg. Co. v. Bair, 437 U.S. 267, 272-73, 98 S.Ct. 2340, 2343-45, 57 L.Ed.2d 197 (1978). This “minimal connection” requirement is fulfilled “so long as the intrastate and the extrastate activities formed part of 'single unitary business.” Mobil Oil Corp., 445 U.S. at 438, 100 S.Ct. at 1232.
“The unitary business rule is a recognition of two imperatives: the States’ wide authority to devise formulae for an accurate assessment of a corporation’s intrastate value or income; and the necessary limit on the States’ authority to tax value or income which cannot in fairness be attributed to the taxpayer’s activities within the State.”
Allied-Signal, — U.S. at-, 112 S.Ct. at 2259. If the business activities are of a *592unitary nature, the due process clause allows a state to apportion a taxpayer’s total income, that is income from both within and without a state’s boundaries, to determine the part of the total income derived from activities in the state. Exxon Corp. v. Department of Revenue of Wisconsin, 447 U.S. 207, 223, 100 S.Ct. 2109, 2120, 65 L.Ed.2d 66 (1980).
In In re Income Tax Protest of Ashland Exploration, Inc., 751 P.2d 1070, 1072 (Okla. 1988), this Court stated the test for determining when a business was unitary in nature as follows:
A business that operates in more than one state is a “unitary business” for income tax purposes when operations conducted in one state benefit and are benefited by operations in one or more other states where the various aspects are so interdependent and of such mutual benefit that they are considered to form one integral business.
Three factors are to be considered in applying this test: “(1) functional integration; (2) centralization of management; and (3) economies of scale.” Allied-Signal, — U.S. ——, -, 112 S.Ct. 2251, 2260, 119 L.Ed.2d 533 (1992).
The United States Supreme Court addressed the issue of whether Idaho could tax income earned outside its boundaries in AS-ARCO, 458 U.S. at 322-24,102 S.Ct. at 3112-13. Idaho State Tax Commission attempted to tax dividends paid to ASARCO by Southern Peru. ASARCO owned a majority interest in Southern Peru. ASARCO’s primary business in Idaho was the operation of a silver mine. Southern Peru produced “blister copper” in Peru, 20-30% of which it sold to Southern Peru Copper Sales Corporation in which ASARCO also owned a majority interest. About 35% of Southern Peru’s output was sold to ASARCO at trade prices. Neither Southern Peru nor ASARCO controlled the prices. ASARCO had a controlling interest in Southern Peru but did not assert control. “ASARCO did not ‘control Southern Peru in any sense of that term’ ” and did not give direction or approval -to Southern Peru on major decisions. The Court concluded “that ASARCO’s Idaho silver mining and Southern Peru’s autonomous business [were] insufficiently connected to permit the two companies to be classified as a unitary business.” Id. at 322.
Also in ASARCO, the Idaho Tax Commission attempted to tax dividends paid to AS-ARCO by M.I.M. Holdings. ASARCO owned 52% of M.I.M.’s stock. M.I.M. engaged “in the mining, milling, smelting, and refining of copper, lead, zinc, and silver in Australia” and “operate[d] a lead and zinc refinery in England.” Id. About 1% of M.I.M.’s output was sold to ASARCO at open market prices. M.I.M. was staffed and operated by Australian people. ASARCO did not manage M.I.M. even though it could have done so. The companies did not have any common director or officers. The Court determined that, because “the business relation [was] nominal, it [was] clear that M.I.M. [was] merely an investment” and not part of ASARCO’s Idaho silver mining operation.
In F.W. Woolworth Co. v. Taxation and Revenue Dep’t of New Mexico, 458 U.S. 354, 102 S.Ct. 3128, 73 L.Ed.2d 819 (1982), New Mexico attempted to tax dividends paid to Woolworth by foreign subsidiaries. In considering the “functional integration, centralization of management, and economies of scale,” the Court found that the subsidiaries’s operations were not interrelated with the parent company. Id. at 370.
In addressing the functional integration of the parent company and the foreign subsidiaries, the Court noted that “no phase of any subsidiary’s business was integrated with the parent’s”; each subsidiary made its own decisions concerning merchandise, store location, advertising and accounting independent of the parent company; each subsidiary had its own accounting department, financial staff, and legal staff; there was “no centralized purchasing, manufacturing, or warehousing of merchandise”; there was no centralized personal training program; and “each subsidiary was responsible for obtaining its own financing from sources other than the parent.” The Court concluded that the operations were not functionally integrated. Id. at 365-66, 102 S.Ct. at 3135-36.
In addressing “centralization of management and achievement of other economies of *593scale,” the Court noted that “each subsidiary operated as a distinct business enterprise at the level of full time management”; at most one officer of one of the subsidiaries was also an officer of the parent company; “[t]here was no exchange of personnel”; each subsidiary trained its own managers; and each subsidiary made its own policies. On the other hand, the parent company and some of the subsidiaries had several common directors; there was frequent communication between the upper management of the subsidiaries and the parent; and “the amount of dividends to be paid by the subsidiaries and the creation of substantial debt ... had to be approved by the parent.” Id. at 366-69, 102 S.Ct. at 3136-38.
The Court also noted that “the parent company’s operations [were] not interrelated with those of its subsidiaries so that one’s ‘stable’ operation is important to the other’s ‘full utilization’ of capacity.” Id. at 370, 102 S.Ct. at 3138. There was no centralization of purchasing and services with the intent to increase profits through economies of scale. In reviewing these facts, the Court concluded that there was no unitary operation which would allow New Mexico to apportion taxes from the foreign corporations.
Turning now to the present case, based on functional integration, centralization of management, and economies of scale, Griffin Grocery, Griffin Manufacturing, and Van Burén Wholesale were not a unitary operation. Griffin Grocery’s corporate headquarters were located in Muskogee, Oklahoma, and its legal counsel was located in Oklahoma City. Griffin Manufacturing was a food manufacturer with all of its plant, facilities, and administrative offices located in Muskogee, Oklahoma. Griffin Manufacturing produced and sold food items.
Van Burén Wholesale was a wholesale food distributor with all of its real and personal property located in Van Burén, Arkansas. All of Van Burén Wholesale’s products were sold to supermarkets. All of Van Burén Wholesale’s employees lived in Arkansas. None of the employees of Van Burén Wholesale worked for Griffin Manufacturing, and none of Griffin Manufacturing’s employees worked for Van Burén Wholesale. The hiring, firing and salary decisions for employees of Van Burén Wholesale were all made by management personnel of Van Burén Wholesale.
Van Burén Wholesale had seven or eight sales persons who serviced its customers. All of the sales persons resided in the Van Burén, Arkansas area. None of the sales persons for Van Burén Wholesale sold any products for Griffin Manufacturing. Griffin Manufacturing had its own sales people, none of whom sold for Van Burén Wholesale.
Van Burén Wholesale purchased less than one per cent of its inventory from Griffin Manufacturing. These purchases were treated the same as purchases from other suppliers. Griffin Manufacturing treated sales to Van Burén Wholesale as it did sales to other customers.
Van Burén Wholesale prepared invoices for the sale of its merchandise in Van Burén, Arkansas. Only Van Burén Wholesale’s employees prepared purchase orders for Van Burén Wholesale. The purchase orders were printed in Van Burén Wholesale’s offices. No one in Muskogee, Oklahoma, had anything to do with the purchase of merchandise or inventory by Van Burén Wholesale nor did anyone in Muskogee have to approve the purchases.
The executive vice-president and general manager of Van Burén Wholesale, Harold McDowell, lived in Van Burén, Arkansas. He traveled to Oklahoma only once or twice a year to review Van Burén Wholesale’s budget.
Van Burén Wholesale’s decisions on extending credit were done exclusively by personnel in its office. Van Burén Wholesale paid its suppliers through a bank account in Van Burén, Arkansas. Although Van Burén Wholesale’s employees prepared the checks to pay bills and invoices, the checks were written on a Muskogee bank. None of Griffin Manufacturing’s bills were paid on or through bank accounts of Van Burén Wholesale. Van Burén Wholesale maintained separate accounting books and records.
Griffin Manufacturing and Van Burén Wholesale had no common employees or officers except William A. Buckley who was *594Executive Vice President of Griffin Grocery and President of Van Burén Wholesale but took no part in the management of Griffin Manufacturing. No officer of Van Burén Wholesale, with the exception of William A. Buckley, officed, lived or spent any substantial amount of time in Muskogee, Oklahoma.
Until his death on July 27, 1985, John T. Griffin, a Muskogee resident, was the President and Chief Executive Officer of both Griffin Television and Griffin Grocery Company. John T. Griffin had the authority to override decisions of the management of both Griffin Manufacturing and Van Burén Wholesale. However, neither John T. Griffin nor the Board of Directors of Griffin Grocery Company exercised control over the day-today operations of Griffin Manufacturing or Van Burén Wholesale.
The only administrative service provided by Griffin Grocery to Van Burén Wholesale was the issuing of payroll checks. Van Bu-rén Wholesale paid Griffin Grocery a fee for this service.
Griffin Grocery sold all of Van Burén Wholesale’s assets in the fiscal year ending June 30, 1986. Only one employee of Van Burén Wholesale, Harold McDowell, was offered a position with Griffin Grocery or Griffin Manufacturing. He was offered employment by Griffin Grocery, as an employee and consultant on an “as needed” basis.
The Commission recites several allegations which they contend support its position. The stipulated facts which the Commission references favoring its view are “John Griffin, as President and Chief Executive Officer of Griffin Grocery Company, had the authority to override decision of the management of either Griffin Manufacturing or Van Buren Wholesale.” As noted in ASARCO and F.W. Woolworth, “the potential to operate a company as part of a unitary business is not dispositive_” F.W. Woolworth, 458 U.S. at 362,102 S.Ct. at 3134; ASARCO, 458 U.S. at 322-23, 102 S.Ct. at 3112-13.
The Commission also relies on several other facts, including the fact that the employees of Griffin Manufacturing and Van Burén Wholesale were employees of Griffin Grocery. Given that the businesses were separate in almost all other respects, these few factors do not change the character of the operations. Like in F.W. Woolworth, 458 U.S. at 369, 102 S.Ct. at 3137, “[ejxcept for the occasional oversight ... that any parent gives to an investment in a subsidiary, there is little or no integration of the business activities or centralization of the management” of the parent and the subsidiaries. Van Burén Wholesale is a separate operation from Griffin Grocery and Griffin Manufacturing, and there is no centralized management or control. The Commission is attempting to tax income which was not derived from a unitary operation in violation of the Due Process Clause and section 2358(A)(4)(c) of title 68 of the Oklahoma Statutes. The gain from the sale of Van Burén Wholesale was allocable entirely to the State of Arkansas and should not be apportioned between the states of Oklahoma and Arkansas.
The Commission’s order denying the refund is reversed, and the cause is remanded with instructions to refund the protested taxes.
ORDER OF TAX COMMISSION REVERSED. CAUSE REMANDED WITH INSTRUCTIONS TO REFUND THE PROTESTED TAXES.
LAVENDER, V.C.J., and OPALA, ALMA WILSON and WATT, JJ., concur. KAUGER, J., concurs in result. SIMMS and HARGRAVE, JJ., concur in part, dissent in part.