dissenting.
I respectfully dissent.
Defendant United Urban Indian Council, Inc., (Tenant) appeals the trial court’s order overruling its motion for new trial in this commercial landlord-tenant dispute. The court awarded judgment for $6,380 to Plaintiffs, Jack D. Fudge and Jo S. Fudge d/b/a Fudge Enterprises (Landlord), on their claim for breach of the lease, and denied Tenant’s counterclaim to recover allegedly overpaid rent. Having reviewed the record and applicable law, I would affirm.
Initially, it should be noted that Tenant has not briefed the first, second, and fifth errors proposed in its petition in error. Those propositions are therefore deemed abandoned. State ex rel. Remy v. City of Norman, 642 P.2d 219, 222 (Okla.1981).
Landlord’s petition alleged that the parties had executed a written office lease agreement in May 1984. The term of the lease was three years. Landlord claimed that Tenant had defaulted on its lease obligations, and prayed for $6,380 allegedly past due.
Tenant denied Landlord’s allegations and asserted that the parties had, in effect, executed an oral modification of the lease. Tenant concluded that the obligation claimed by Landlord had been satisfied and that Tenant had in fact overpaid by $580, for which it counterclaimed against Landlord.
At trial, Jack Fudge testified that Tenant had leased two offices, totalling 2,321 square feet, for a lease term from July 1, 1984, through June 1987. The rent totalled $1,740. Two years into the term, in July 1986, Tenant vacated the smaller office and began tendering rent of $1,160. Fudge testified that “[w]e were in negotiations from oh, several months prior to them vacating the suite.... Originally, we both tried to rent the space. If we were able to re-rent it before they vacated it and we didn’t lose any rent, then there would have not been any problem.... ” Fudge had instructed his bookkeeper to accept the lesser rent because he was “trying to salvage them as a tenant." He said that his company did not regularly send out bills, but that if they had given one to Tenant, the bookkeeper would have delivered it.
Landlord had unsuccessfully attempted to re-lease the premises. Fudge also stated that he had submitted a proposal to Tenant in which the rental on the smaller office was forgiven if Tenant would release the larger space for an additional three years. The proposal was never accepted by Tenant.
Tenant then presented the testimony of its executive director, Robert Giago, who had signed the 1984 lease. He testified as to the negotiations and representations surrounding the execution of the lease. The parties stipulated that Tenant’s federal funding grant had been reduced in 1986. According to Giago, the reduction precipitated Tenant’s reduction in office space. He had notified Jack Fudge of this on two separate informal occasions.
*271Giago testified that Tenant had received a rent statement from Landlord for every month of the lease period, and that, beginning in July 1986, Landlord’s statement reflected a balance due of $1,160. Giago never received any correspondence indicating that Landlord expected additional rent, or any objection to the lesser amount when paid.
Tenant had vacated the remaining leased office in April 1987, three months prior to the lease’s end. On April 7, Giago sent Fudge a letter enclosing rent for April and May. The June rent, based on the original monthly amount due, had been prepaid at the inception of the lease; the $580 difference between the $1,740 prepaid and the $1,160 paid during the final year of occupancy formed the basis for Tenant’s counterclaim. Tenant again received no correspondence concerning default after vacating the premises.
The trial court found in favor of Landlord on both the primary action and the counterclaim, and entered judgment accordingly. Tenant filed a motion for new trial, which was denied. From these rulings, Tenant appeals.
In an action at law tried to the court with the jury waived, the finding of the court is as binding on appeal as the verdict of a jury. If there is any competent evidence to support the finding, it will not be disturbed on appeal. Pracht v. Oklahoma State Bank, 592 P.2d 976, 978 (Okla.1979).
On appeal, Tenant argues that the executed oral reduction of rent constitutes a modification of the lease agreement, and that the Landlord’s failure to object to the reduced rent and the vacation of the premises, coupled with its acceptance of the lower amount, waived the right to the recovery sought. Conversely, Landlord argues that its proposed lease extension/liability release and its attempt to mitigate damages by re-leasing the vacated space indicate an intent to hold Tenant to the original contract terms.
I find Tenant’s first argument unpersuasive. A written contract may only be modified by another written contract or by an executed oral agreement. 15 O.S.1981 § 237. Such an agreement must be proven by positive, clear and convincing evidence. Dewberry v. Universal C.I.T. Credit Corp., 415 P.2d 978, 979 (Okla.1966). There is competent evidence in the record to support a finding that Landlord never orally agreed to a modification of the rental terms. Jack Fudge expressly denied doing so, and Giago merely stated that he “told” Jack Fudge of Tenant’s intent to vacate the premises, and that Fudge “understood” the reduction of space and rent.
However, the real crux of Tenant’s argument is that Landlord’s actions in billing and accepting the lower rent, along with its failure to object to the arrangement, waived any right to assert a claim for the unpaid balance of the original rent obligation. A party may waive a right either by acts which indicate an intent to relinquish it, or by such failure to insist upon it that the party is estopped to afterwards assert it. Steiger v. Commerce Acceptance of Oklahoma City, Inc., 455 P.2d 81, 89 (Okla.1969) (quoting Scott v. Signal Oil Co., 35 Okl. 172, 128 P. 694 (1912) (syllabus D).
If a tenant wrongfully abandons the leased premises before the expiration of the term, the landlord, at his election, may terminate the lease, enter and take possession, recovering accrued rents to the date of entry; do nothing to terminate lease or disturb possession and sue for the entire term when due; or give notice to the defaulting tenant that surrender is refused, and sublet the premises for the tenant’s benefit. Carpenter v. Riddle, 527 P.2d 592, 593-4 (Okla.1974). Landlord did not re-enter the premises but rather exercised the second option available to it under Carpenter. Since Landlord had the right to do nothing to terminate the lease, it cannot be said that such inaction indicated an intent to relinquish the right to sue at the end of the lease term.
Further, the trial exhibits were withdrawn after trial and do not appear in the record before us. Without a copy of the lease before us, it cannot be determined whether the obligations concerning the two offices were severable. Landlord’s acts in *272accepting the partial rent may be viewed merely as a recognition of the remainder of the lease obligation, rather than an affirmative relinquishment of the right to seek damages for breach of any part of the contract. Landlord notified Tenant that release of the lease obligation for the smaller office was contingent upon a lease extension for the remaining office. The trial court’s refusal to find that Landlord had intentionally waived its right to seek damages for breach was supported by competent evidence.
Under the above definition of waiver, a party may also waive a contract right by such failure to insist upon it that the party is estopped to afterwards assert it. In order to show such an estoppel, however, Tenant must show that it detrimentally relied on Landlord’s silence regarding the reduced rent. Other than its continuing breach of contract, Tenant presented no evidence to show such a detriment.
I would affirm the judgment of the trial court.