LONDON (AP) — A group of influential British lawmakers wrote a letter to the financial regulator yesterday expressing concern at last week's lifting of a ban on short selling of financial stocks, which was immediately followed by a sharp sell-off in leading bank shares.

John McFall, chairman of the Treasury Select Committee that oversees British economic and financial matters, urged Hector Sants, the chief executive of the Financial Services Authority, to reintroduce the ban if hedge funds were found to be responsibility for the excessive volatility in the banking stocks.

McFall said the committee, made up of lawmakers from across the political spectrum, said he was particularly concerned to hear anecdotal evidence that some hedge funds have been shorting British bank stocks — trading on the expectation that their share prices will fall.

"In the light of the extreme market turbulence in bank shares in the week since the ban was lifted, could you please confirm that the Financial Services Authority is actively monitoring the connection between the volatility in bank shares and the repeal of the ban on short selling," McFall said.

"Could you also please confirm that you will not hesitate to reintroduce the ban if it is found that short selling has contributed to the undermining of stability in the banking sector," he added.