(Adds detail on U.S. settlement)
By Steve Slater and Douwe Miedema
LONDON/WASHINGTON, Nov 11 (Reuters) - British and U.S.regulators are poised to levy hefty fines on leading banks in alandmark settlement after a year-long global investigation ofallegations of collusion and manipulation in the foreignexchange market.
At least one of the six banks set to be named early onWednesday by Britain's Financial Conduct Authority (FCA) wasstill in 11th-hour negotiations over details of the deal, twosources close to the matter said.
The banks - UBS, Barclays , Royal Bank ofScotland, Citigroup, JPMorgan and HSBC - will only sign off on an expected combined penalty of1.5 billion pounds ($2.4 billion) late on Tuesday, sources said.
It would be the first settlement over allegations ofmisconduct in the $5.3 trillion-a-day foreign exchange market.
The Wall Street Journal reported on Tuesday that Swissfinancial regulator FINMA had sent warning letters to around 10past and present UBS employees about potential enforcementaction for alleged misconduct in the forex market.
A spokesman for FINMA declined to comment. Britain's FCAalso declined to comment.
U.S. regulators and FINMA are also expected to be amongthose close to concluding investigations. Any U.S. settlement isexpected to name at least one other bank, a source told Reuterslast week.
Bank of America has said it was in "advanceddiscussions" with U.S. bank regulators.
The U.S. Commodity Futures Trading Commission was likely toallege false reporting and manipulation, lawyers said, the twomost applicable options under U.S. law, which it also used inits settlement over Libor benchmark rates.
This is in contrast to UK authorities, which can look atcharges such as failure to put in place the right controls. Thetwo U.S. banking regulators are likely to go after the banks forfailing to prevent bad conduct.
The U.S. Office of the Comptroller of the Currency is likelyto settle charges with Bank of America, Citi and JPMorgan.
The Federal Reserve will be responsible for any settlementwith the units of the four foreign banks. But it was not clearwhether the Fed would announce its deal at the same time.
(1 US dollar = 0.6299 British pound) (Additional reporting by Douwe Miedema in Washington, JoshFranklin in Zurich; Writing by Kirstin Ridley; Editing by DavidHolmes, Leslie Adler and Dan Grebler)