News: UPDATE 1-Australia's ANZ and NAB named in U.S. class action for BBSW trading

(Add details on NAB class action and ASIC charges)

SYDNEY, Aug 18 (Reuters) - Australia and New Zealand Banking Group (ANZ) and National Australia Bank (NAB) were named in a U.S. class action relating to trading in bank bill swap rates (BBSW), they said on Thursday, adding to ongoing court action by the Australian regulator.

ANZ and NAB, two of Australia's largest financial institutions, told the Australian stock exchange that they were among a group of 17 banks being sued by two U.S.-based investment funds and an individual derivatives trader.

Both banks, along with Westpac Banking Corp (WBC), are already facing charges laid by the Australian Securities and Investments Commission (ASIC) for allegedly trying to profit by manipulating the same benchmark interest rates.

Recent investigations into the rigging of foreign-exchange markets and benchmarks across the world have ensnared major global lenders and led to billions of dollars in fines.

Westpac Banking Group declined to say whether it is also involved in the U.S. class action. Commonwealth Bank of Australia, the nation's second largest lender, was not immediately available to comment.

The BBSW is the primary interest rate benchmark used in Australian financial markets to price home loans, credit cards and other financial products.