Two days after Yahoo’s search collaboration with Google went down in flames, Steve Ballmer appears to be holding all the cards.

Speaking in Sydney, Australia, Friday, the Microsoft chief executive was quoted by Reuters as saying he had no interest in renewing his failed effort at acquiring Yahoo.

“We are not interested in going back and re-looking at an acquisition,” he said.

That left Yahoo Chief Executive Jerry Yang in a lurch. After Google formally pulled away from a search partnership with Yahoo on Wednesday, Mr. Yang publicly reached out with an olive branch to Microsoft. “The best thing for Microsoft to do is to buy Yahoo,” Mr. Yang said, according to a Bloomberg report.

Yahoo’s stock fell $1.78, or 12.8 percent, to $12.18 Friday afternoon. The Internet company has been under pressure to revive its business in short order after Mr. Yang and the rest of the board rejected Microsoft’s $31 per share offer, which later was raised to $33 per share. In June, Microsoft declared it no longer would pursue the deal.

In an effort to remain independent, Yahoo cut a multi-year deal with Google to outsource part of its search advertising, an arrangement that was expected to provide it with $800 million per year in incremental income. That agreement fell apart when the Justice Department said it would file an anti-trust lawsuit if the parties went forward.

In another search-related skirmish, The Wall Street Journal reported that Microsoft is trying to woo Verizon Wireless away from a planned search deal with Google.

Google, which dominates the online search and search-advertising business, had been in talks for months with Verizon to make its search engine the default setting for most phones in the carriers line-up. Microsoft, however, is offering sweeter financial terms, according to sources quoted by The Journal.

Yahoo ranks a distant second behind Google, but Mr. Yang has been betting on a turnaround in the business of the Sunnyvale, California, company. In the midst of the Microsoft acquisition offer, Yahoo faced a proxy fight from billionaire investor Carl Icahn, who favored a sale. Ultimately, Yahoo settled the proxy fight by granting seats on its 11-member board to Mr. Icahn and two allies.