UK regulators and global banks are discussing a wholesale overhaul of the calculation and regulation of interbank lending rates, amid allegations that the benchmark for $350tn contracts worldwide may have been subject to manipulation.

The review comes as regulators in North America, Europe and Japan have expanded their year-long probes into alleged manipulation of the London Interbank Offered Rates, and other benchmark lending rates, which help set the price of financial products including mortgages and credit cards.

The Libor rate-setting process is not considered a regulated activity under the UK Financial Services and Markets Act, but US and European banks and interdealer brokers have suspended or fired more than a dozen traders in recent months following allegations of abuse.