
73 S.E.2d 472 (1952)
236 N.C. 558
INTERNATIONAL MINERALS & METALS CORP.
v.
WEINSTEIN et al.
No. 456.
Supreme Court of North Carolina.
November 26, 1952.
*474 Ehringhaus & Ehringhaus, Raleigh, for defendants, appellants.
Smith, Leach & Anderson, Raleigh, for plaintiff, appellee.
DENNY, Justice.
The only assignment of error brought forward and argued in the appellants' brief is based upon their exceptions to the failure of the court below to sustain their motion for judgment as of nonsuit.
The defendants contend that the "supplemental oral agreement" left the delivery date indefinite, and converted the original contract into one for the purchase and sale of materials at a stated price, delivery to be made at the convenience of the seller. We do not concur in this view.
We construe the supplemental oral agreement to do nothing more than to extend the time of delivery temporarily and to assure the defendants that during the time of such extension, the plaintiff would not exercise its right to go into the open market and purchase the materials. The plaintiff's evidence tends to show that each time the defendants were contacted prior to 25 October, 1948, they promised to make shipment. But, on the above date, the plaintiff's agent was informed by the defendants that shipment would not be made until the market went down to where it was when the contract was made. There is nothing in the alleged supplemental oral agreement, or in the testimony of the defendants, to indicate that the time for delivery was in any way made dependent upon the status of the market. Neither is there anything in the evidence offered by the defendants to indicate that the failure to make delivery was due to the other business matters in which the defendants were engaged when the time for delivery was extended.
Manifestly, it was the duty of the defendants to act with reasonable promptness and diligence to comply with the terms of their contract. And when the plaintiff extended the time for delivery for the reasons stated, it was under no obligation to wait any longer than was reasonably necessary under the existing circumstances for the defendants to comply with their agreement. "If no time for the performance of an obligation is agreed upon by the parties, then the law prescribes that the act must be performed within a reasonable time." Rocky Mount Savings & Trust Co., v. Aetna Life Insurance Co., 199 N.C. 465, 154 S.E. 743, 745; Erskine v. Chevrolet Motors Co., 185 N.C. 479, 117 S.E. 706, 32 A.L.R. 196; Winders v. Hill, 141 N.C. 694, 54 S.E. 440. Certainly the defendants are in no position to complain because they were extended additional time to carry out the terms of their contract. This is particularly true since the extension of time was given in response to their promise to ship the materials. Neither can it be seriously contended that the plaintiff did not give the defendants a reasonable time in which to ship the materials after the extension of time for shipment was given on 11 June, 1948.
We hold that when the defendants informed the agent of the plaintiff that they would not ship the materials described in the contract until the market fell to where it was when the contract was made, such action constituted a breach of the original contract and of the supplemental oral agreement. And the fact that the plaintiff notified the defendants that the materials contracted for would be accepted if shipped prior to 15 November, 1948, did not constitute a waiver of the breach, if the materials were not shipped, so as to prevent the plaintiff from going into the open market at any time within sixty days from and after 25 October, 1948 and purchasing the materials as it was authorized *475 to do under the terms of the original contract.
The case was submitted to a jury in a trial free from prejudicial error. And the facts and contentions of the respective parties were considered by the jury, and the issues answered against the defendants. The verdict will be upheld.
No Error.
PARKER, J., took no part in the consideration or decision of this case.
