LONDON Regulators are trying for a fourth time to revive stalled plans for common global accounting rules so that investors and regulators can compare companies and spot problems more easily.
Leaders of the world's leading 20 economies (G20) met in 2009 at the height of the financial crisis and set a deadline to align differing rules by the end of that year.
But disagreements between two key rulesetters scuppered that timetable and revised deadlines for mid-2011 and mid-2013 were also missed, leading to Monday's move to set a deadline for a deadline.
The Financial Stability Board, a G20 task force, said efforts by the International Accounting Standards Board (IASB)and the U.S. Financial Accounting Standards Board (FASB) were diverging, such as in forcing banks from around 2015 to recognize losses far earlier than under current rules.
Both rulesetters reached a common approach but at the last minute in July FASB had second thoughts and went its own way.
There is also disagreement over how banks should show investors their derivatives holdings: on balance sheet - the IASB's preferred option - or via footnotes as sought by FASB.
The difference means that Deutsche Bank's balance sheet appears 30 percent smaller under U.S. rules.
"The FSB reiterates the benefits of a timely completion of convergence and considers it important that the convergence programme not lose momentum in other areas," FSB chairman Mark Carney told G20 finance ministers meeting in Mexico on Monday.
"The FSB will request by no later than end June 2013 a joint IASB-FASB report on all outstanding items with a specific timetable for completion," Carney, also Bank of Canada governor, said.
Stephen Haddrill, chief executive of Britain's accounting regulator, the Financial Reporting Council, said on Monday that the IASB had abandoned its goal of convergence.
Alignment is closely tied with efforts to persuade America to take the next step and switch to using IASB rules.
"We are waiting for Godot. That is we are waiting for the United States," IASB Chairman Hans Hoogervorst told the European Parliament's economic affairs committee on Monday.
The United States in the summer deferred its decision on whether to adopt the London-based board's standards after raising hopes for years.
"I think in the end we will get the Americans on board," Hoogervorst said.
The G20 push is part of wider scrutiny of accounting firms, criticized for giving banks a clean bill of health just months before they needed taxpayer support in the financial crisis.
Hoogervorst said the firms could have been much more active in pointing out problems at banks to regulators but everyone must share the blame.
"As long as regulators said everything was hunky dory they did not have a big incentive to raise the red flag," he added.
(Editing by David Cowell)