Northern Rock's chief executive Adam Applegarth has resigned as a non-executive director of Persimmon.
Adam Applegarth denied anything could have been done
"We understand his desire to focus fully on the issues at Northern Rock PLC," the housebuilder's chairman said in a statement to the stock exchange.
Mr Applegarth was one of four Northern Rock executives criticised by a committee of MPs this month.
Northern Rock sought emergency funding from the Bank of England last month, leading to a run on the bank.
When the four directors appeared before the Treasury Select Committee it emerged that they had all offered to resign in September but had been asked to stay on to deal with the bank's problems.
The resignation of Northern Rock chairman Matt Ridley was accepted two weeks ago.
The bank's management has defended its policy of borrowing large sums of money on the financial markets to lend as mortgages to house buyers.
That policy left it vulnerable when the credit crunch led to the effective shut down of the markets from which Northern Rock borrowed its money.
Most lenders raise more of their money from savers' deposits.
Northern Rock has until February to assess options for its future, including a sale.
It has received approaches from several groups, including a consortium led by Richard Branson's Virgin Group.