An interest-free loan of 500 million pesos (about $39.3 million) was made to the STPRM oil workers union to help meet demand for workers' housing, state-owned oil giant Petroleos Mexicanos, or Pemex, said.

The Mexico City daily Reforma first reported the interest-free loan last Thursday.

The union presented a proposal for improving workers' housing during collective bargaining negotiations, Pemex said.

Under the terms of the collective bargaining agreement, the company "would lag by approximately 15 years in satisfying demand for housing, as well as generating additional rights for newly hired workers," Pemex said in a statement.

"It made sense to grant a loan to the union with the goal of covering the housing needs of workers, especially those in areas where there is no supply or infrastructure, in the shortest time possible," Pemex said.

Management and the union signed the collective bargaining agreement on July 27, 2011, granting the STPRM a five-year interest-free loan, with repayment scheduled from January 2016 to November 2020, Pemex said.

The STPRM is led by Carlos Romero Deschamps, who was elected president in 1996 and has managed to stay at the union's helm despite being involved in a number of corruption scandals, such as the so-called "Pemexgate."

The "Pemexgate" scandal involved the diversion of more than $100 million in union funds to the campaign of Francisco Labastida, who was the presidential candidate of the Institutional Revolutionary Party, or PRI, in the 2000 election and lost to Vicente Fox, of the National Action Party, or PAN.

The PRI was fined 1 billion pesos (about $78 million) in 2003 for irregularities in financing the 2000 campaign.

Juan Jose Suarez Coppel, who served as Pemex's CEO under former President Felipe Calderon, of the PAN, was replaced last December by Emilio Lozoya.

President Enrique Peña Nieto, a member of the PRI, appointed Lozoya to run the state-owned oil giant.

Peña Nieto has made Pemex's modernization one of his administration's priorities. EFE