The new contract will run until July 2014, with the option to extend for up to a further six months until February 2015.
Landmarc will continue to support the Defence Infrastructure Organisation (DIO) to manage military training facilities across the MoD's 160,000 hectares of built and rural UK training estate, a position it has held since 2003.
Previous work done by Landmark has included the creation in Norfolk of an Afghan village that replicates the operating environment in the Middle East to enable realistic training.
Landmarc supports about 7.5 million training days per year, delivering consultancy, management and operation of training areas and ranges as well as explosives safety, built and rural estate management, catering, information management, administration services, project and commercial property management.
The contract covers over 120 sites, including more than 8,000 buildings worldwide.
Steve Utley, project director at Landmarc said: "Initiatives we've launched include Landmarc 100, our rural business innovation scheme, supporting BiTC by providing a Rural Business Connector in Northumberland and a new rural hub network for local entrepreneurs, all of which are designed to make a positive social and economic impact across the estate and surrounding areas. We look forward to our increased involvement and the opportunity to contribute to the continued success of the estate across the UK."
Interserve CEO Adrian Ringrose said tha Interserve has been working in the defence and security market for more than 25 years. "Partnering with the MoD requires a more intelligent approach to support services and contracts like these demonstrate the full range of our service capability. This is not only about providing support to MoD operations at facilities both here in the UK and overseas, but also the ability to support the vital training that is needed to prepare the military for operational success."