President Barack Obama moved to fill two key posts in the ranks of financial regulators as officials work to complete new rules required by the Dodd-Frank Wall Street oversight law.

The White House announced on Friday that Obama will nominate Thomas Curry to head the Office of the Comptroller of the Currency, the agency that supervises nationally chartered banks.

Obama also will nominate Mary Miller to become Treasury Undersecretary for Domestic Finance, the White House said in a statement.

Curry, a member of the Federal Deposit Insurance Corp board and a politically registered independent, had been rumored to be a top contender for the OCC post.

The OCC regulates the nation's largest banks, such as Bank of America and JPMorgan Chase, and has been without a permanent head since August last year, when John Dugan left the post.

Curry's challenge will be changing the OCC's reputation as a friendly regulator that tries to shield large banks from state consumer protection laws.

Earlier on Friday, a group of Democrats including Representative Barney Frank wrote to the OCC, asking for more time for the public to weigh in on a proposal that critics say still gives the OCC too much power to preempt state laws.

Miller, currently Treasury's assistant secretary for financial markets, is in charge of managing the country's public debt.

She will be nominated to the broader role as Congress and the administration struggle to hash out a deal to raise the $14.3 trillion debt ceiling and rein in government spending.

Curry and Miller join other financial policymaker nominees in the pipeline, including two members for the Securities and Exchange Commission and one commissioner for the Commodity Futures Trading Commission.

Obama has also nominated FDIC Vice Chairman Martin Gruenberg to head the FDIC when Sheila Bair leaves her chairman post next week. Bair welcomed Curry's nomination on Friday, saying his exemplary record in state and federal banking regulation makes him an excellent choice for Comptroller.

Senate Banking Committee Chairman Tim Johnson on Friday said he plans to move forward on Curry's nomination as quickly as possible.

Frank said Curry had excellent bipartisan credentials and urged quick action on his nomination, saying, it would be inappropriate to have an acting comptroller making important decisions on implementation of the Wall Street reform law.

BIGGEST NOMINATION BATTLE LOOMS

Obama has yet to address the most hotly debated opening -- the top job at the new Consumer Financial Protection Bureau, which will regulate products like mortgages and credit cards and opens its doors on July 21.

Democrats are pushing the administration to nominate Harvard law professor Elizabeth Warren, whom Wall Street has painted as an inexperienced firebrand who will harm markets.

She would have a difficult time winning Senate confirmation but so will almost any nominee.

Last month, 44 Republicans said they would block any nominee to be director of the new bureau unless legislation is enacted changing how it is structured, a move Democrats say is intended to weaken the watchdog.

Republicans are expected to continue to take a tough stance against almost all Obama nominees for top financial policy posts.

Of the nominees announced, Gruenberg is expected to have the easiest path to confirmation due to his years as a congressional Senate aide and the relationships he built with Republicans during that time.

Curry, 54, joined the FDIC in 2004 after serving as the Massachusetts Commissioner of Banks for several years. Being a registered independent could lessen Republican opposition.

He was, however, a registered Democrat between 1993 and 1999, according to disclosure forms he filed with the Senate in 2003 for his nomination to join the FDIC board.

(Reporting by Dave Clarke, additional reporting by Rachelle Younglai; Editing by Tim Dobbyn, Gerald E. McCormick and Carol Bishopric)