The UK is to allow the extradition of three former NatWest bankers to the United States to face trial over fraud charges relating to U.S. energy company Enron (search).

The three are "devastated but not surprised" and will appeal, said their spokeswoman, Melanie Riley.

Britain's Home Secretary Charles Clarke upheld a ruling by a UK judge last October that the three could be extradited.

The bankers' case falls under UK legislation in force since January of last year, which was originally designed to speed up the transfer of suspected terrorists to the United States.

This law has left the Home Secretary with only limited powers to overrule court decisions on extradition.

Former bankers Gary Mulgrew, Giles Darby and David Bermingham -- who worked for NatWest Bank (search), which is now part of Royal Bank of Scotland (search) -- have been fighting the extradition, which would require them to face trial in Houston, Texas.

The three, who deny the fraud allegations, have argued that they should face trial in the UK.

They are alleged to have conspired with Enron executives, including former finance chief Andrew Fastow (search), over the sale of a stake in an Enron entity in 2000.