Microsoft unveiled its improved search engine called "Bing' this week and is doing so without the help of Yahoo's search engine, as negotiations for a possible deal are stalled.

"Negotiations always ebb and flow and right now they're in an ebb position,' Yahoo chief executive Carol Bartz told Yahoo's Tech Ticker on Wednesday. "There's not that much going on.'

Bartz and Microsoft chief executives both appearing at the conference spoke at the Wall Street Journal's '˜D: All Things Digital conference' in Carlsbad, California, saying they were open to some sort of deal but did not disclose details.

Microsoft is trailing behind rivals Yahoo and search leader Google.

Google had more than 64.2 percent of all U.S. Internet searches in April, or 9.5 billion out of 14.8 billion total searches, data firm comScore reported recently. Yahoo had 20.4 percent while Microsoft came in third place with 8.2 percent.

Microsoft could make headway in the search market by reaching an agreement with Yahoo, which is showing signs of improving fundamental strength, wrote J.P. Morgan analyst Imran Khan in a research note earlier this week.