drive -official@ (Adds announcement unlikely this week, background)
WASHINGTON, Oct 25 (Reuters) - President Donald Trump is unlikely to pick economic adviser Gary Cohn as his nominee for Federal Reserve chairman because Cohn is playing a crucial role in the White House tax reform effort, a senior administration official said on Wednesday.
"No decision has been made and no candidate has been ruled out but Garys role is too crucial to getting tax reform done. It might be too important for him to continue to be the lead, for him to announce a change at this time," the official said.
The Republican president is looking to announce a Fed chair nominee before leaving on a trip to Asia on Nov. 3, in order to give his choice time to go through the Senate confirmation process. Current Fed Chair Janet Yellen's term ends in early February.
But an announcement is unlikely this week, said another source familiar with the situation.
Trump told Republican senators during a private lunch on Tuesday that his focus for a new Fed chair was on Stanford University economist John Taylor, Fed Governor Jerome Powell and Yellen, a source familiar with the meeting said.
When Trump asked the senators for a show of hands on whether they would prefer Taylor or Powell, the most support went for Taylor, the source said.
Cohn irritated Trump by criticizing the president's response to violence in Charlottesville, Virginia, in August at a white supremacist rally.
But the two men in recent weeks seemed to have ironed out their differences, with Trump singling out Cohn for praise for his help in the tax reform effort.
Trump is also considering a fifth candidate for the Fed job, former Federal Reserve Governor Kevin Warsh, sources have said.
Trump told Fox Business Network that he admired Yellen but that the decision to pick a new Fed chair was something to which he would like to contribute.
You like to make your own mark, which is maybe one of the things shes got a little bit against her, but I think she is terrific. Weve had a great talk and we are obviously doing great together, you look at the markets, Trump told the network.
(Reporting by Steve Holland; Editing by James Dalgleish and Peter Cooney)