Delta Air Lines has raised its stake in Aeroméxico in a deal worth $620 million.

The purchase of 32% of shares gives the US carrier ownership of 36.2% of the Mexican airline.

Delta also has the option to raised its holding up to 49%.

Chief executive, Ed Bastian, said: “We are pleased to successfully complete the tender offer.

“This is yet another milestone that strengthens the Delta- Aeroméxico relationship as we move toward implementing our joint cooperation agreement in the second quarter.”

Delta and Aeroméxico started codeshare flights in 1994 before entering into a deeper commercial pact six years ago.

Delta then invested $65 million in shares of Grupo Aeroméxico, the parent company of Aeroméxico, in 2015.

A joint co-operation agreement covering flights between the US and Mexico was unveiled two years ago.

The flights pact has been reviewed by regulatory authorities in the US and Mexico and will be implemented in the second quarter of the year, Delta said.