The agency will handle direct activity across its brands, including Churchill, Direct Line, Green Flag and Tracker.
The brief will also include promotional activity and new brand partnerships.
MRM Meteorite won the account after a shoot-out against OgilvyOne. Kitcatt Nohr Digitas was knocked out earlier in the process. A review of the account began in April.
The win is the agency's first major new-business triumph since McCann Worldgroup acquired Meteorite in November last year and merged it with MRM.
Geronimo currently handles DM for Direct Line and Tracker. Green Flag does not have a dedicated DM agency and has previously opted to use its ad agency, CHI & Partners, for any direct work.
CHI also handles Churchill's DM account, having won the business in 2010.
A consolidation of the DM account follows the rebranding earlier this year of RBS Insurance Group as Direct Line Group.
MRM Meteorite declined to comment.Follow @SaraKimberley