A person familiar with the matter told Reuters that the deal was signed originally in March, closing the 14-year-long dispute, but did not disclose final settlement details.

A Siemens spokesman refused to confirm the settlement value.

Siemens sued Pemex for $690m for additional expenses incurred earlier.

The issue began with Pemex filing a lawsuit against Conproca in 2012 in the US alleging corruption and cost overruns related to the Cadereyta refinery reconfiguration project (CRRP). It has contended that the joint venture has paid bribes to Pemex officials.

Conproca was launched by the two partners to bid for the CRRP located on the outskirts of Monterrey, Mexico’s northern state of Nuevo Leon. The refinery reconfiguration project involved construction of ten new plants, expansion of four plants and building a 1,317km crude oil pipeline.

The US courts have dismissed the suit observing that the claims made by Pemex are insufficient to run a case in the US courts.

A three-judge panel then said: "The activities involved in the alleged scheme-falsifying the invoices, the bribes, the approval of the false invoices-took place outside of the US."

In 2008, Siemens paid $1.6bn to the US and European authorities to settle similar allegations of paying bribes in several countries.