SEAT has withdrawn its factory team from the World Touring Car Championship.
The Spanish manufacturer had been expected to quit the series since the end of last season, but delayed its final decision until this week.
The firm will continue to give technical support to customer teams who run its petrol or diesel-powered Leons in the WTCC.
SEAT Sport director Jaime Puig said: "After achieving all possible successes in the WTCC, we are now going to focus all our efforts on customer sports in different championships.
"We are always eager to win when a SEAT is on the track and to do so, SEAT Sport will provide all of our customers with the necessary technical support."
SEAT has won the last two WTCC titles with Yvan Muller and Gabriele Tarquini, but has been at the center of an ongoing row over the equalization of its turbo diesel cars with the category's normally aspirated petrol machinery throughout both seasons.
Its cars were granted a variable limit to their turbo boost pressure in the first three races of 2009, provoking rival manufacturer BMW to threaten to quit the series when it learned of the waiver. The limit was then reduced, prompting SEAT to issue its own quit threats.
SEAT's communications director Dominik Hoberg added: "SEAT will continue with a noteworthy presence in motorsport in 2010 but the company will have a different approach as regards to its motorsport activity."