The US intends to take a flexible approach to interpreting global guidelines on bankers’ bonuses, a move likely to frustrate European nations that want clearly defined standards to be applied globally.

Washington’s approach to the guidelines may give US banks the ability to pay bonuses to some types of employees more rapidly than their competitors outside America.

By contrast, the UK rushed out a statement last night proclaiming the agreement of Britain’s top five banks to apply early the bonus restrictions agreed at last week’s G20 meeting in Pittsburgh, in a bid to become the first member nation to promise implementation.

The UK Treasury said the banks – Barclays, HSBC, Standard Chartered, the part-state-owned Royal Bank of Scotland and Lloyds – would apply the rules to the 2009 bonus round and “set the standard for all other UK and international financial institutions to follow”.

The conditions, the bulk of which are already enshrined in UK regulatory practice, include a ban on multi-year guaranteed bonuses and the deferral of bonuses over three years with clawback rights.

One person involved in the talks said they lasted into the early hours of Wednesday, after some banks without government stakes protested about the terms. “We are happy to comply in principle,” said one banker, “but it is essential that it is enforced in the same way across the G20.”

The standards, endorsed by G20 leaders last Friday, include a requirement that “a substantial portion of variable compensation, such as 40 to 60 per cent” should be paid over periods of three years or more.

However, a US administration official told the Financial Times that it regards the 40-60 per cent range as “an example” of what was meant by “substantial” and not a range into which all pay deals should fall. This view is shared by the Federal Reserve, the main regulator for the largest US banking groups.

European negotiators had pressed hard for numerical guidelines to be formally backed by the G20 in order to establish a level playing field between banks in different jurisdictions.

On pay, the US is sticking to its belief that it does not make sense to impose one-size-fits-all requirements.

The lingering disagreement is not so much about the very top executives. Tim Geithner, Treasury secretary, says a majority of top bankers’ pay should vest over time.

Rather, differences remain about the extent to which supervisors should mandate formulas for other highly paid staff. The US view is that the nature of the businesses involved is so diverse that banks need the flexibility to come up with the right package for each employee.