NEW YORK/WASHINGTON - Five of the biggest banks in the United States are putting finishing touches on plans for going out of business as part of government-mandated contingency planning that could push them to untangle their complex operations.

The plans, known as living wills, are due to regulators no later than July 1 under provisions of the Dodd-Frank financial reform law designed to end too-big-to-fail bailouts by the government. The living wills could be as long as 4,000 pages.

Since the law allows regulators to go so far as to order a bank to divest subsidiaries if it cannot plan an orderly resolution in bankruptcy, the deadline is pushing even healthy institutions to start a multi-year process to untangle their complex global operations, according to industry consultants.

"The resolution process is now going to be part of the cost-benefit analysis on where banks will do business," said Dan Ryan, leader of the financial services regulatory practice at PricewaterhouseCoopers in New York. "The complexity of the organizations will shrink."

JPMorgan Chase & Co, Bank of America Corp, Citigroup Inc, Goldman Sachs & Co and Morgan Stanley are among those submitting the first liquidation scenarios to regulators at the Federal Reserve and the Federal Deposit Insurance Corp, acco rding to people familiar with the matter.

The five firms, which declined to discuss their plans for this story, have some of the biggest balance sheets, trading desks and derivatives portfolios of financial institutions in the United States.

Great Britain and other major countries are imposing similar requirements for "resolution" plans on their big banks, too.

The liquidation plans are coming amid renewed questions about the safety of big banks following JPMorgan's stunning announcement last month that a trading debacle has cost it more than $2 billion - a sum far too small to endanger the bank, but shocking enough to bring back memories of the financial crisis.

A nod to glass-steagall

If the extensive planning and review process works as proponents hope, big banks will become less hazardous to the public and regulators will be more confident that they can let wounded institutions die without wrecking the economy.

In congressional hearings earlier this month, JPMorgan CEO Jamie Dimon said that the bank's contingency plan for going out of business would let it fail without cost to taxpayers. Living wills reduce the systemic risk of a big bank failing, Dimon said.

The living will requirement could actually yield similar results to restoring Glass-Steagall without actual re-enactment of the Depression-era laws separating commercial banking from investment banking, former FDIC Chairman Sheila Bair told Reuters TV earlier this month.

Bair said regulators may determine that for a liquidation plan to work, a bank must separate traditional banking and insured deposits into subsidiaries set apart from volatile securities trading and securities underwriting.

The rules push banks to untangle their complex structures, which can include thousands of legal entities, and which, in Bair's opinion, have effectively blocked proposals for breaking up the corporations.

Whether the Fed and the FDIC would actually force any banks to sell businesses or cordon off insured deposits remains to be seen, cautioned Richard Herring, a banking professor at the University of Pennsylvania.

"We don't know if they will have the guts to do it, but the tools are there," said Herring, a leading proponent of living wills for more than a decade, who was appointed to an FDIC advisory panel on the plans.

Herring worries , too, that the plans will be so long and complex that they will overwhelm the staff at the agencies.

Still, that the plans are being written at all is progress, Herring said.