* Limited progress toward global standard for insurers
* Industry seeks to establish common capital rules
* Differing U.S., European practices make going tough
LONDON, Sept 11 (Reuters) - The first global standard for investors to compare how much capital insurers from different countries hold to keep policies safe is caught in a transatlantic tussle, casting doubt on whether it is practical, industry and regulatory officials say.
Global banks have used common "Basel" capital rules for decades, and the $180 billion bailout for insurer AIG during the 2007-09 financial crisis prompted regulators to embark on a similar standard for insurers in 2013 for the world's top 50 insurers.
But four years into the work there is no completed International Capital Standard (ICS) nor a firm date for its introduction, making it harder for investors and policyholders to compare insurers from different parts of the world.
"The sense is there has been a collective pause around the ICS following elections in the United States and the European Union, as well as Brexit," said Mike Consedine, chief executive of the National Association of Insurance Commissioners (NAIC), which groups U.S. state-level regulators.
Slow progress has triggered speculation within the industry that regulators may tell insurers the process is now on hold when they meet in Kuala Lumpur in November.
Hugh Savill, director of regulation at the Association of British Insurers, a trade body, said the ICS lacked sufficient political support for now to drive it through to completion.
"There is a serious stalemate, and I see us no nearer agreement than two years ago," Savill said.
Others were openly critical.
"It's a mess. The U.S. won't play and the ICS is going nowhere," said the chief executive of a European insurer.
"I don't think you will get a material change in global capital because nobody can afford it."
Few believe, however, that a new capital rule would lead to big hikes in requirements.
The ICS is being written by the International Association of Insurance Supervisors (IAIS) whose chair, Victoria Saporta, a Bank of England executive director, said a significant step forward was taken in July when the first version of the ICS was published for field testing.
"There is no question that arriving at an ICS that achieves greater convergence than that of the different group capital standards adopted in different jurisdictions and regions is a challenging task," Saporta told Reuters.
"But it is also a necessary one if policyholders of international groups are to be better protected, whilst also enjoying the more inclusive offering that can result from the greater capital efficiencies of international diversification."
CARRY ON TALKING
The IAIS has yet to come up with a single approach to calculating the amount of capital the world's top 50 or so insurers will have to hold.
It is testing two "approaches" for valuing liabilities such as future payouts on policies.
The first approach is based on U.S. accounting rules, while the second is based on market prices, similar to EU capital rules known as Solvency II.
But without as yet unclarified adjustments, the two approaches would come up with different capital requirements and leave investors scratching their heads.
"Is there a bridge between U.S. accounting and Europe's Solvency II? There is none that is economically sound," said Tobias Buecheler, head of regulatory strategy at German insurer Allianz.
"It's unclear how those approaches can be combined, aligned. You have a divide between the United States and Europe."
Insurance industry officials say the IAIS should instead focus on managing risks from the sector's activities, seen as more fruitful regulatory territory.
Insurers point out that AIG was the only insurer bailed out in the financial crisis, and this was because it had moved into non-core, riskier hedge fund activities.
Cristina Mihai, head of international affairs at Insurance Europe, a trade body, said it would be hard to have an ICS based on just one approach.
Finding a common approach is becoming more difficult.
NAIC announced a few weeks ago it was teaming up with the Federal Reserve to write a new U.S. capital rule, and Consedine made clear that any global rule would have to fit in with what this double act comes up with, not the other way round.
"We have stressed the need previously for the ICS to be principles-based and to give countries a certain level of jurisdictional flexibility. That's going to be critical for the United States," Consedine said.
Complications loom in Europe, too.
European insurers will begin using a new accounting rule in 2021 known as IFRS 17, representing a major overhaul of how income is calculated. The EU's Solvency II rules will be reviewed, meaning there could be changes with knock-on effects for the ICS.
"There are more goalposts and they are all moving, that is the problem," Allianz's Buecheler said.
Consedine said NAIC remains committed to the goals of the ICS, but it must result in something that is "workable for the United States and for regulators". (Reporting by Huw Jones; editing by Mike Collett-White)