Delta Air Lineshas closed its tender offer for nearly a third ofAeromexicoGroup, investing roughly USD 620 million in the Mexican carrier.

Atlanta-basedDeltaacquired 228 million additional shares in Aeromexico’s holding company under the oversubscribed offer that closed on 10 March, it says today. It now holds a 36.2% stake in the airline.

Airtickets ONLINE

“This is yet another milestone that strengthens the Delta-Aeromexico relationship as we move toward implementing our joint cooperation agreement in the second quarter,” says Ed Bastian, chief executive ofDelta, in a statement.

AeromexicoandDeltawill launch an immunised joint venture covering their flights between Mexico and the USA on 1 April.

Deltapaid Ps53 (USD 2.70) per share for the additional stake inAeromexicounder the offer that was launched on 13 February.

The US carrier has the option to acquire an additional 12.8% stake inAeromexicoGroup for a 49% share in the airline.

Deltafirst disclosed plans to increase its stake inAeromexicoin November 2015. It initially invested USD 65 million in the Mexican carrier in 2012.

The story has been updated to reflect an investment of USD 620 million, not USD 260 million as initially reported