Robert Diamond, who quit this week as chief executive officer of Barclays Plc, sought to blame other banks for misleading markets about their ability to borrow and regulators for turning a blind eye.

Ordered to testify to British lawmakers after Barclays agreed to pay a record 290-million-pound ($455 million) fine for rigging the London interbank offered rate, Diamond said yesterday he was “disappointed” regulators failed to act on repeated warnings from Barclays that competitors had lowballed their submissions. Legislators challenged him on why he took so long to uncover his own firm's attempts to manipulate the rate.

“This isn't just Barclays,” Diamond, 60, told lawmakers at a three-hour hearing of Parliament's Treasury Select Committee. “Throughout 2007 and 2008, no institution of the 16 banks reporting three-month dollar Libor was at the higher end more consistently than Barclays. Barclays was getting questions about why it was always high and we were saying, 'We are high because we were reporting at where we were borrowing money.”'