In the high stakes poker game with Yahoo, Carl Icahn refuses to fold his hand.

The billionaire investor filed more proxy papers Thursday afternoon, a clear indication that he intends to pursue his fight to dislodge Yahoo’s board of directors and its chief executive, Jerry Yang.

Meanwhile, Bill Gates, in his last day as Microsoft’s chairman, reportedly said that a deal between Microsoft and Yahoo is not likely.

Earlier in the week, Yahoo had filed proxy materials urging shareholders to reject Mr. Icahn’s board nominees given the newly concluded deal to outsource some search advertising to Google and the failure to reach an acquisition deal with Microsoft.

In his filing, Mr. Icahn substituted Keith Meister for Robert Shaye on his list of nine board nominees. Mr. Meister’s name earlier had been withdrawn from Icahn’s slate of 10 nominees after Yahoo trimmed the size of its board to nine. Mr. Shaye was forced to pull his name, however, when his former employer, Time Warner. informed him that serving on Yahoo’s board would put him in competition with its AOL unit, a violation of his non-compete agreement. Mr. Shaye served at Time Warner as co-chairman and co-chief executive offer of its New Line Cinema unit.

Reuters reported that Mr. Gates made his remarks to NBC’s Tom Brokaw. Mr. Gates, who founded the company with Paul Allen, will continue to serve as non-executive chairman.

Yahoo holds its shareholder meeting August 1.