Media planning and buying will by handled McCann's sister agency Universal McCann.
Proton has launched two new marques successfully this year, the Persona and the Saga, but has a lot of do to reverse its fortunes after the financial turmoil of recent years.
Proton is set to launch an MPV model later this year, and will also want to boost its profile overseas where the company has enjoyed more success.
Earlier rounds of a grueling three-month affair had involved JWT and TBWA-ISCMalaysia, while Leo Burnett's sister agency Black Pencil and Ogilvy & Mather pulled out after attending the initial briefing session.