Delta Air Lines is buying a stake in Aeromexico and expanding its existing partnership with the carrier.

Through a memorandum of understanding announced this week, Delta plans to invest $65 million to gain a roughly 3.5 percent stake in Aeromexico. It would be Delta's only stake in another airline.

In the deal, subject to Mexican regulatory approval, Delta would gain a seat on the board of directors.

Delta chief executive Richard Anderson said in a written statement that the deal builds the foundation for a joint venture.

Delta and Aeromexico are already partners in the SkyTeam global alliance and have a "code-share" marketing partnership in which they sell seats on each others' flights.. The two airlines will expand the code-sharing and work together more closely by co-locating airport facilities and other moves.

The carriers also plan to open a new maintenance, repair and overhaul facility together in Mexico. Each airline will invest equal shares for the facility. Aeromexico already does some overhaul work in Mexico on Delta planes, while Delta does engine work on Aeromexico planes in Atlanta, and the partnership would expand that work.

Mexico's Secretary of Tourism, Gloria Guevara, met with Delta officials in Atlanta on Wednesday and said the airline's investment in Aeromexico "speaks of the growth and the potential that they see in Mexico."

She said Mexican and U.S. airlines have nearly covered the gap in service left by the the shutdown last year of Mexico's then-largest air carrier, Mexicana.