The New York Red Bulls defender is in Mexico City working on a deal that will land him with Club Leon, according to a source close to the negotiations. He is expected to sign a two-year deal.
Elias Ayub, co-owner Carlos Slim's chief aide, is believed to be in Mexico's capital to finalize the move.
Marquez, one of the Red Bulls' three Designated Players, has been a disappointment since signing with the Major League Soccer team from Barcelona in 2010. He has played just 35 of a possible 73 games while earning $4.6 million, the second-highest salary in MLS.
Marquez had been linked to return to Club Atlas - the place where the Mexican international began his professional career - over the past two offseasons.
With an open DP spot, the Red Bulls may look to convince Brazilian star Kaka to leave Real Madrid. Kaka has an apartment in New York, and his brother Digao plays for the Red Bulls.