American Airlines Group Inc.’s vice president overseeing alliances is stepping down, a month after the carrier lost a pending partnership expansion in Latin America to rival Delta Air Lines Inc.

Joe Mohan will move to an advisory role at the carrier after this week, “offering assistance until early next year,” according to a memo obtained by Bloomberg News. The change comes two weeks after American announced a reshuffling of executive duties in which Mohan was to begin reporting to Vasu Raja, who was promoted to senior vice president of network strategy at American.

“I have the highest confidence this team and this structure will result in providing the best product and service to our customers and return to our shareholders,” according to the note this week from Mohan, who joined American in August 2016 as vice president of alliances and partnerships.

Pressure on American—already high from a flight-disrupting work slowdown by mechanics—increased last month when Latam Airlines Group SA reached a $2.25 billion partnership agreement with Delta. The deal threatens to erode American’s power as the dominant carrier in South America.

An effort by American and Latam to jointly market and operate flights between the U.S. and six South American countries foundered in May when Chile’s Supreme Court hobbled the venture on antitrust grounds.

American fell 1.5% to $28.20 at 1:32 p.m. in New York. The stock fell 11% this year through Monday, the only decliner among a Standard & Poor’s index of the five largest U.S. carriers. The group has risen 8.1% this year.

American on Oct. 10 said four executives would share responsibility for areas now overseen by Kerry Philipovitch, who will retire at year-end as senior vice president of customer experience.

Mohan previously was an executive at the Viva group of discount carriers in Latin America and served as chief commercial officer for Copa Airlines in Panama. He began his career in the industry at Continental Airlines in 1996, according to American.