By Huw Jones and Rachelle Younglai

LONDON/WASHINGTON (Reuters) - The United States and Europe are moving at different speeds down possibly divergent paths toward dealing with troubled multinational financial giants, despite promises of transatlantic coordination.

The prospect has some prominent experts in the field of financial regulation worried, with a key U.S. congressional committee scheduled to vote as soon as next week on a new Obama administration plan for dealing with "too big to fail" firms.

"Negotiations to create a unified cross-country resolution process should begin immediately," said a report released this week by the Squam Lake Working Group of 15 academics.

The group urged rapid adoption of at least one measure that could be shared and equally effective in any country.

"Every major bank holding company should be required to regularly file a 'living will' detailing how the bank should be legally resolved in the event of distress.

"Other systemically important institutions ... should also file these plans," said the report, whose authors include Yale University economist Robert Shiller, author of the 2000 book Irrational Exuberance, and Martin Baily, former chairman of the Council of Economic Advisers in the Clinton administration.

Governments worldwide are wrestling with the problem of what to do with large financial firms -- such as JPMorgan Chase (JPM.N: Quote, Profile, Research, Stock Buzz), Morgan Stanley (MS.N: Quote, Profile, Research, Stock Buzz) and Goldman Sachs (GS.N: Quote, Profile, Research, Stock Buzz) -- whose global reach has the potential to destabilize markets.

Authorities want new frameworks that apply lessons from last year's credit crunch to prevent future bailouts.

"They have to align them, at least in large part," said John Dearie, executive vice president at the Financial Services Forum, representing CEOs of the largest financial firms.

The U.S. House of Representatives Financial Services Committee is crafting a bill that would create a systemic risk monitoring council and empower the government to impose stricter rules on firms that could threaten the wider economy. It would also give it the authority to shut them down if necessary.

Britain is emphasizing the need for banks to draw up "living wills," or contingency plans for winding down a bank's or financial firm's position quickly in an emergency.

The G20 group of leading countries agreed in September that systemically important financial firms should have contingency plans in place by the end of next year. Several UK-based banks are expected soon to start drawing up living wills.

The 27-nation European Union is discussing a pan-EU risk monitoring board. But it will have no powers to force a bank to take action, let alone break one up or wind it down.

A planned new pan-EU banking authority is also in the cards. But so far it would only have binding powers to adopt rules for day-to-day activities and could not force a national bank to take action that would oblige a national bailout. It would have a role in a crisis, but details are unknown.

"The EU is moving ahead, but the problem is, it's not a single state," said Graham Bishop, a former banker and financial regulation expert.

"The new authorities will have powers to issue instructions in a crisis situation, but this is where the whole issue of burden sharing becomes extremely relevant," he said.

In contrast, the Obama administration has made decisions on detailed issues, including that the largest firms should fund the resolution of failed peers; that stockholders and creditors would take a hit in a resolution; and that the government could not put money into a failing firm unless it is in receivership and on a path to be unwound, sold or liquidated.

Regulators would also have to hold systemically important firms to higher capital standards and force firms to retool if their behavior poses a risk to the financial system.

Efforts toward more global approach are under way. The Financial Stability Board, which coordinates G20 policies, is expected to come forward with recommendations by October 2010.

The Basel Committee on Banking Supervision made 10 recommendations last month to help banks and regulators draft resolution plans by the G20 deadline next year.

(Reporting by Huw Jones in London and Rachelle Younglai in Washington; Editing by Dan Grebler)