The purchase of the £2.1m-turnover DM printer follows SPI UK's expansion from the wholesale into the retail market, which began in January 2010.
Following the acquisition, SPI UK intends to expand its services to retail clients to include database management and processing, laser and digital printing, polywrapping, enclosing, finishing and overseas mail consolidation.
Paul Taylor, chief executive of SPI UK, said: "MCM Direct's values are closely aligned to those of Swiss Post International – a quality-driven organisation that builds trust and long-term relationships with its customers and suppliers.
"It's a perfect fit that puts us in an improved position to succeed in the retail market. With MCM Direct, we will be able to offer industry customers efficient outsourcing services."
Martin Collier, managing director of MCM Direct, was unavailable at the time of writing but will continue in his role following the acquisition. SPI UK and MCM Direct will be merged from January 2011.
Daniel Baettig, head of international mail at Swiss Post International, said: "The acquisition of MCM Direct is part of our strategy to further grow Swiss Post International in the UK.
"We want to better penetrate the country by building up a network of subsidiaries, partners and resellers for our products and services."
SPI UK has also announced a partnership with the managed mail services provider Direct Entry Services.
