Sources said he is considering a number of offers, but it is not known if he is planning to return to the UK.
Mukherjee worked at Wieden & Kennedy's Amsterdam headquarters for seven years, working on accounts including Nike and Coca-Cola. His role included working on domestic and international business as well as overseeing projects in London.
He started his career in media planning and buying at BMP DDB Needham in 1986, before being promoted to head of press in 1993.
In 1995, Mukerjee moved to O&M Media to head up press. This was followed by a senior media role at MindShare, which he left in 1999 to join Wieden & Kennedy.
The company declined to comment. Mukherjee could not be reached.