Commercial Metals Co. is rebuffing billionaire investor Carl Icahn's $1.73 billion takeover offer, saying the proposal undervalues the scrap-metal processor.

On Friday Icahn told Commercial Metals' board that it had until Monday to set up a meeting to discuss his $15 per share offer, which was a 7 percent premium to Friday's closing stock price of $13.99.

A call to Icahn Enterprises LP, which made the offer, was not immediately returned.

Icahn, known for buying and shaking up struggling companies, already owns almost 10 percent of Commercial Metals. He had wanted to combine Commercial Metals with his existing metals recycling businesses and sell off the rest of its assets, refocusing on its core North American operations. Icahn already owns PCS Metals Inc.

Commercial Metals is based in Irving, Texas.