Chicago Mayor Rahm Emanuel speaks at a press conference where he addressed issues related to the city's murder rate and the city's Sanctuary City policy on January 25, 2017 in Chicago, Illinois.

Long-time democratic politician and former Chicago Mayor Rahm Emanuel will join investment bank Centerview Partners, a source familiar with the matter told CNBC Wednesday.

Just a month after leaving the mayor's office of Chicago, Emanuel will be advising clients on mergers for Centerview, co-founders of the firm told the Wall Street Journal, which first reported the news.

Centerview has offices in New York, London, San Francisco, Palo Alto and Los Angeles and will be opening an office in Chicago.