UPDATE 1-Stellantis appoints Carlos Zarlenga as new North America COO

(Adds confirmation that Mark Stewart is leaving Stellantis)

MILAN, Jan 16 (Reuters) - Stellantis has appointed Carlos Zarlenga as its chief operating officer for North America, replacing Mark Stewart, to leverage "further improvements" in its performance in the region, the carmaker said on Tuesday.

The new appointment will be effective from Feb. 1.

In a statement, group CEO Carlos Tavares thanked Stewart and wished him "the best in his new position." Stewart is leaving the automaker, but Stellantis did not comment further about Stewart's future or the reasons for the leadership change.

Stewart has been North America COO for three years, since the formation of Stellantis through the merger of Fiat Chrysler and Peugeot maker PSA.

"In the very demanding North American market with many obstacles to overcome in order to foster the performance of the company, Carlos Zarlenga is the best leader among our talent pool to replace Mark Stewart and to drive the change in our business model towards electrification in the region," Tavares said in the statement.

After weeks of coordinated strikes, which cost the group billions in terms of lost production, Stellantis in October reached salary increase agreements with unions in the United States and Canada.

"Carlos Zarlenga has demonstrated his ability to bring together and unite diverse teams and to deliver the expected results," Stellantis added in its statement.

It described Zarlenga, a graduate of Belgrano University in Buenos Aires, as a "seasoned leader", with more than a decade's experience in several regions and a "strong financial background".

He joined the Franco-Italian automaker in 2022 as President of Stellantis Mexico.

"He has delivered a year-on-year improvement in sales performance, market share and AOI [adjusted operating income], leading to the best profit level ever recorded in Mexico," the carmaker said.

(Reporting by Giulio Piovaccari in Milan and Joe White in Detroit; Editing by Emelia Sithole-Matarise and Sharon Singleton)