LONDON/HONG KONG (REUTERS) - US plans to delay globally-agreed reforms to make banks safer after the financial crisis will throw a system of international regulatory cooperation into confusion, European Union and Asian regulatory sources said on Tuesday.

But the rollback will be welcomed by global banks as it will allow them to cut back on how much expensive capital they must hold to support their business, the sources said.

Since the financial crisis watchdogs around the world have been working via the G20 group of leading economies to increase cooperation between regulators following the collapse of Lehman Brothers in 2008.

But the US Treasury unveiled plans on Monday to upend the country's financial regulatory framework in a 150-page report that suggested more than 100 changes.

"Trump's proposals are going in the wrong direction," Jakob von Weizsaecker, a German Social Democrat in the European Parliament's economic and monetary affairs committee, told Reuters. "In Europe, we must be careful not to forget the lessons of the financial crisis. It would be a huge mistake for us to follow the US lead on this."

The US Treasury has called for a delay implementing a globally agreed rule on bank liquidity which requires banks to cover long term funding needs from January 2018.

The US Treasury also wants to delay a fundamental review of banks' trading books, which was also agreed globally through the Basel Committee of international regulators.

This trading book review represented a major overhaul of how banks set aside capital to cover risks from stocks, bonds and other instruments kept in their trading businesses.

The US Treasury said these two rules would have added new capital and liquidity requirements to existing rules banks have to follow.

The European Union has already proposed a draft law to implement these pieces of regulation.

Valdis Dombrovskis, the EU's financial services chief, said the Treasury's lengthy proposals would be studied in detail. "It must be noted that we need to follow what the developments will actually be, whether those recommendations will really be taken on board," Dombrovskis told reporters.

An EU source said the recommendations were "a bit worrying"and raised question marks about regulation.

The Basel Committee could not be reached immediately for comment.

Asia-based regulatory experts said the US Treasury's position would lead some watchdogs in their region to review their implementation timelines. They are already unhappy about having the West's post-crisis reform agenda imposed on them.

"This is going to create level-playing field problems, and concerns for global banks when dealing with fragmented regulatory regimes in the region," Kevin Nixon, global & APAC lead, centre for regulatory strategy at Deloitte in Sydney, said.

Even so, any rollback on the fundamental review of banks'trading books by Asian regulators would generally be a boon for global banks operating in the region, Keith Pogson, senior partner, Asia Pacific financial services at EY in Hong Kong, said.

The US Treasury will also review a mechanism for winding down failed banks.

"Depending on how the review is implemented, it can create quite a lot of trouble for cooperation between supervisors," the EU source said. "We are looking at this with quite a bit of potential concern. It could jeopardise the whole international cooperation on resolution of banks."

Many of the other reforms proposed by the US Treasury are domestic, such as scaling back on "gold plating" of globally agreed rules.

The US Treasury review also suggested the country's so-called "Volcker Rule" needed amending to avoid damaging market liquidity. The Volker Rule restricts banks' ability to make bets in financial markets with their own money.

An EU version of the Volker Rule is currently before the European Parliament.

The US Treasury also proposed easing capital requirements on US branches of foreign banks which hold US$4.5 trillion in assets.

At present, the Federal Reserve requires them to ring-fence capital onS soil inside an "intermediate holding company", but the US Treasury wants changes to encourage foreign banks to increase investment in US markets and provide credit to the economy.

The EU has proposed similar requirements for foreign branches in the bloc, and the US move could prompt a rethink of those plans in Europe.