AT&T Corp. shares rose 8.1 percent after reports that the company is considering selling a 10 percent to 15 percent stake in its wireless unit to the public.

AT&T shares rose $4.25, to $57.43 3/4, in New York Stock Exchange trading of more than 12.4 million shares, making it the most active stock. Earlier, the shares touched $58, a four-month high. Sources close to the company told The Washington Post on Tuesday that AT&T would issue a tracking stock for its wireless holdings. The Wall Street Journal today quoted sources as saying the company is considering an initial public offering of the shares.

Such a wireless IPO could be the largest ever in the United States, raising as much as $10 billion.

"With AT&T's stock price having come down considerably from its high, this is a tool they were taking down off the shelf," said Mel Marten, an analyst at Edward Jones & Co., who rates AT&T a "strong buy." "They'd certainly like to raise a lot to help fund capital expenditures."

In January, the company scrapped plans to issue a tracking stock in connection with its $59.4 billion purchase of cable television operator Tele-Communications Inc., which was completed in March.

AT&T shares rose 12 percent Monday, the biggest jump this decade, after AT&T's cable Internet-service provider, Excite At Home Corp., said it would issue tracking shares for the Internet businesses it acquired from Excite Inc.

Selling shares in its wireless division would let AT&T separate that business's performance from the rest of the company, which is judged on earnings per share. It could then invest more in advanced wireless technology and network expansion, without concern about dilution.