A bridge building firm is expected to plead guilty to charges of overseas corruption and breaching United Nations sanctions.

In a ground-breaking case for the Serious Fraud Office (SFO), Mabey & Johnson is understood to have agreed a plea bargain over charges that it bribed Ghanaian and Jamaican officials.

It is also expected to admit a separate charge relating to payments made to Saddam Hussein’s regime in Iraq.

Mabey, which makes bridges based on Sir Donald Bailey’s portable Bailey bridges, used by Allied armies in the Second World War, is expected to face a hefty fine.

It is due to appear at Westminster Magistrates’ Court today.

Sources close to the case confirmed that Mabey had agreed to enter guilty pleas to the charges.

It is thought to be the first such plea bargain won by the SFO.

The case is also believed to be the first significant instance where a UK company has been prosecuted on overseas corruption charges and it is also the first case brought relating to the UN’s Oil for Food investigations.

Reading-based Mabey is alleged to have made improper payments between 1994 and 2001 in relation to contracts obtained in Ghana and Jamaica.

The SFO’s investigation was triggered by the firm’s appearance in a UN report on the Oil For Food scandal in Iraq.