Asset manager BlackRock Inc and U.S. private equity firm First Reserve have taken a joint stake worth around $900 million in the second phase of Mexico pipeline project Los Ramones, state-controlled oil company Pemex said on Twitter on Thursday.

In a separate statement, Pemex said the joint stake was equivalent to 45 percent of the costs involved in the construction of the project. It represents BlackRock's first ever infrastructure investment in Mexico, Pemex added.

"The company has the intention of establishing a greater presence in Mexico," Pemex said in the statement.

On Wednesday, Reuters reported that BlackRock Inc, the world's largest asset manager, was looking to invest in infrastructure projects in Mexico.

The move also comes as Mexico's government, which has seen the peso fall to record lows off the back of an oil price slump that has dented the appeal of its energy sector opening, sets about courting private investment.

Pemex said in September it would spend $2.5 billion on the second phase of the Los Ramones pipeline, which will eventually run from the U.S.-Mexico border to central Mexico to help satisfy growing demand for gas by boosting cheap imports from the United States.