UK to investigate Barclays bosses over Libor fixing

LONDON, June 28 (Reuters) - British authorities must find out which executives at Barclays knew about its attempts to manipulate key market interest rates, British finance minister George Osborne said on Thursday, warning that criminal proceedings could follow.

"As far as the chief executive of Barclays is concerned, he has some very serious questions to answer today. What did he know and when did he know it? Who in the Barclays management was involved, and who therefore should pay the price?" Osborne told parliament.

"Barclays are not alone in this, the FSA is continuing to investigate the conduct in a number of institutions."

Barclays, whose shares were trading down more than 11 percent, was fined 290 million pounds by U.S. and British authorities on Wednesday after investigations found the bank tried to manipulate key market interest rates.