Young & Rubicam New York is thought to have beaten off competition from fellow WPP-owned ad agencies Ogilvy & Mather Worldwide and J Walter Thompson to take the account for the global launch of the new Jaguar X-Type.
The win has started rumours that Y&R will take the entire $100m worldwide account of the Jaguar brand, owned by Ford.
O&M New York currently handles Jaguar's $75m business in the US, while JWT handles the account in Europe and other markets.
Y&R's executive creative director Ross Sutherland led the pitch. Sutherland worked on the account at O&M before quitting the agency for Y&R last year.
The move comes after Ford moved all its European advertising to O&M's London office. Y&R had handled several big Ford brands after a series of pitches with O&M in recent years, and recently won the $75m Land Rover account.
In 1997 JWT and O&M formed a joint venture to work on Jaguar's marketing and to prevent feuding between the rival agencies. The US and European markets have been highly competitive - the US has higher sales, while the UK is proud of its heritage of the brand's home.