Comcast Corp. and Time Warner Cable Inc., the nation’s two largest cable companies, announced yesterday that they would not participate in the U.S. 700 megahertz wireless spectrum sales, which will take place in January 24.

The auction, which is said to start at $4.6 billion, is seen as the last opportunity for a new cable company to enter the wireless market. The sale is expected to raise up to $15 billion for the U.S. Treasury, according to a published report.

Comcast said in a statement on Monday that it already had “many strategic options” as a member of a cable industry consortium that acquired a piece of wireless spectrum in a Federal Communications Commission auction last year.

"Comcast Corp. has decided not to bid in the 700-MHz wireless auction. The 20 MHz of spectrum acquired in the wireless auction last year with our cable partners in SpectrumCo provides us with significant long-term flexibility and many strategic options. We will continue to explore how wireless can complement our services through various partnerships and consumer trials," D'Arcy Rudnay, a Comcast senior vice president, said in a statement, according to the Philadelphia Inquirer.

Time Warner Cable’s Chief executive, Glenn Britt told investors at a UBS Conference on Monday that the company would not take part in the auction.

Google, the search engine giant, announced on Friday that it would be on the race for the spectrum. The company’s officials expressed their hopes that the new network capacity will allow it to compete directly with existing mobile communications companies.

AT&T and Verizon Communications Inc. are also expected to bid billions of dollars to capture the valuable slices of airwaves, although they have not officially stated their intentions.

The results of the auction are not expected until March next year.