This appeal, while arising from a very complex series of transactions and events, presents a relatively simple question: Whether an optionor may properly refuse to tender its agreed performance under an option contract when:
(a) the optionees (or their successors) cannot agree and each seeks to exercise the option to the exclusion of the other; and
(b) the successor in interest of one of the optionees has executed on part (but not all) of the leasehold estate of the optionee.
We answer the question in the negative and reverse and remand for further proceedings.
In abbreviated form, the transactions and events in order of occurrence, are:
1. Lott Enterprises (as owner and lessor) executed a five-year lease to Wiser Enterprises, Inc. and Emery Wiser as lessees, of a parcel of land upon which lessees planned to (and later did) construct a building.
2. The lease contained an option to purchase either for $31,500 cash or under an installment option.
3. A money judgment was obtained against Wiser Enterprises, Inc., by R.H. Pierce Manufacturing Co., which judgment was duly recorded.
4. The two lessees assigned the lease and option to Continental Manufacturing Company.
5. Pierce levied on the real estate at the execution sale and bid in its judgment amount seeking to purchase the Wiser Enterprise, Inc. interest, in which levy and sale, the notices described a portion (but not all) of the leased premises.
6. Continental gave timely notice of intent to exercise the option in its own (sole) behalf, tendering th% cash purchase price.
7. Pierce gave timely notice of intent to exercise the option in its own (sole) behalf under the time contract option.
Pierce filed an action for declaratory judgment against Continental and Lott, which resulted in counterclaims and cross-claims. Pierce moved for summary judgment on its complaint seeking a declaration that its exercise of the option was valid and enforceable, which motion was denied. Lott moved for summary judgment on its counterclaim and cross-claim for quiet title, which motion was granted, and this appeal followed. Lott contends its obligation to sell the property under the option was excused by the above-described events. We disagree. The power of an option holder is the power of acceptance, and by giving notice of exercise of the option within the agreed time limit, an offer is accepted. 1A Corbin on Contracts (1963 ed.) § 264, p. 508. Moreover, “notice by ... [an optionee] is not merely the acceptance of an offer; it is also the performance of a condition precedent to ... [an optionor’s] duty of immediate performance.” Id. at 509. Therefore, once Lott received notice of exercise of the option by one of the optionees, its offer under the option contract was accepted and it was obligated to perform. The fact that' the second optionee did not join, and in fact *344attempted to initiate its own exercise of the option, did not excuse Lott's performance. Whatever the rights of Continental and Pierce are, vis a vis one another, Lott’s proper action was to tender its agreed performance by way of interpleader, leaving it to the trial court to resolve the dispute as between Pierce and Continental. RESTATEMENT (SECOND) OF CONTRACTS § 339 comment d (1979).
As guidance to the trial court on remand, we would note that “the rights of promisees of a single performance are determined in accordance with the rules of equity,” 4 Corbin on Contracts, supra, § 939, pp. 785-86, and that when one of two co-optionees exercises an option, he cannot do so in derogation of the rights of the other. His exercise of the option is impressed with a trust in favor of the second and if the second thereafter, and in a timely manner on being notified to close, tenders his share of the option price, he is entitled to participate equally in the purchase.
We further note that we are unable to determine from this record whether Pierce accomplished a proper and complete execution on the interest of Wiser Enterprises, Inc. in the option. The option is a contract right which might require execution or levy on something other than the land itself. Since the facts on this issue were not fully developed below, and the issue not adequately briefed on appeal, we leave it for determination by the trial court on remand.
Accordingly, the judgment of quiet title is reversed and the case remanded for further proceedings consistent herewith, including trial on the merits as to the rights of Continental and Pierce inter se regarding the option, and whether the attempted exercise of the option by either Pierce or Continental was procedurally correct in accordance with the terms of the lease agreement and the applicable statutes.
Costs to appellant. No attorney’s fees awarded.
DONALDSON, C.J., and BISTLINE, J„ concur.