Jarvis says it will not pay bonuses to board members until the cause of the Potters Bar rail crash is known.
The rail maintenance contractor came under fire last month when it paid bonuses to the board, including £150,000 to chief executive Paris Moayedi.
Chairman Colin Skellet said: "We have not paid and will not pay any bonuses in relation to the period covered by the Potters Bar tragedy until we are absolutely clear as to what happened and where responsibility lies."
He said Jarvis was co-operating fully with several investigations into the crash, which killed seven people.Jarvis has a bought a 51% stake in Braddons International, the insurance risk management firm, for up to £1m, depending on its performance. Braddons will provide insurance and risk management services on Jarvis' PFI projects.