Mexico's national oil company Pemex is selling a 7.86 percent stake in Spanish oil firm Repsol, worth about 2.2 billion euros ($3.0 billion) at current market prices, Citigroup and Deutsche Bank, the banks handling the sale, said on Tuesday.
The sale, to be carried out through an accelerated book build, is nearly all of the Mexican firm's holding in Repsol, where it is the company's third largest shareholder with an 8.75 percent stake.
Mexican government officials had opened the door to a Repsol stake sale in the past few weeks when Repsol appointed a chief executive officer whom Pemex had not backed.
The sale comes before Mexican President Enrique Pena Nieto is due to make his first official visit to Spain on June 9-10.
Repsol declined to comment and Pemex could not be immediately reached for comment.
Repsol's shares closed on Tuesday down 0.19 percent at 20.865 euros each.
($1 = 0.7342 Euros)
(Reporting by Tracy Rucinski. Editing by Jane Merriman)