Republican economic veterans, Hubbard and Warsh, advising Jeb Bush -sources

(Adds Washington Post report on nonprofit group, paragraphs 11-14)

By Steve Holland, Anna Yukhananov and Lauren Tara LaCapra

WASHINGTON/NEW YORK, March 31 (Reuters) - Glenn Hubbard and Kevin Warsh, veteran Republican economic policymakers and critics of the Fed's ultra-loose monetary policy, have emerged as top economic advisers to likely presidential candidate Jeb Bush, Republican sources said on Tuesday.

Hubbard, who served as the top White House economist for former President George W. Bush, was one of the architects of Bush's tax cuts. Hubbard also advised Mitt Romney in his 2012 bid for the presidency and together with Warsh was mooted as a possible Treasury secretary if Romney made it to the White House.

Hubbard, dean of the business school at Columbia University, has close ties to financial companies, including insurer Metlife Inc and BlackRock Inc, the world's largest money manager.

Warsh served on the Federal Reserve's Board of Governors during the Bush years.

Jeb Bush has been weighing a presidential bid and is expected to make a formal announcement within the coming months.

Two Republicans familiar with the matter confirmed the roles of Hubbard and Warsh. A Bush spokeswoman was not immediately available to comment.

Hubbard, in an emailed statement, would not confirm the connection with Bush, saying he was willing to discuss economic policies with any presidential contender, including Democrat Hillary Clinton.

"I think Governor Bush would be an excellent president, with his focus on economic growth, work, and opportunity. I would be happy to talk with any candidate about economic ideas - including Secretary Clinton," he said.

Warsh was not immediately available to comment.

Bill Simon, a former Wal-Mart chief executive who served on Bush's team when he was governor of Florida, is assembling policy experts for his prospective candidacy, Republican sources said.

The Washington Post reported on Tuesday that Simon set up a nonprofit group called Right to Rise Policy Solutions Inc in Arkansas in February "to highlight conservative policies that will restore economic and social mobility in America."

In an email to the Post, Simon also said the organization "will be engaged in policy generation that is consistent with Governor Bush's optimistic, conservative message and vision for the future of America."

The Post said the group could collect unlimited funds in secret, unlike Super PACs or Political Action Committees, which must name their donors.

It quoted Simon as saying the group would "comply with all applicable IRS regulations." While it can accept unlimited donations, he added the nonprofit "is a policy group. Not a political or fundraising group."