Enrique Pena Nieto, the candidate from the Institutional Revolutionary Party, won the July 1 vote in Mexico. He promised to make oil reform a key issue of his administration in an effort to break a state monopoly.
Calderon's National Action Party has been at odds with Pena Nieto's party. He blamed his rivals for blocking energy reform measures in 2008 but suggested the acrimony was a thing of the past.
"I certainly hope that this kind of attitude can be rectified," he was quoted by the Platts news service as saying. "It's been harmful to the whole nation."
The Mexican government nationalized the oil industry in 1938.
Mexico is one of the top oil-producing nations in the world. Though not a member of the Organization of Petroleum Exporting Countries, it's one of the top three exporters to the United States.
U.S. and Mexican officials in February signed an agreement on the exploration of oil and natural gas along a shared maritime border in the Gulf of Mexico.
Election runner-up Andres Manuel Lopez Obrado is challenging Pena Nieto's victory in court. The next president would take office in December.
Celebrity Breakups and divorces of 2014 [PHOTOS]