Capita said the acquisition will "add reach and scale" to its existing operations in the business travel market and offer additional events and meetings management capabilities.
Expotel's current clients include National Grid, Virgin Media, the Scottish government and BP. Expotel made a pro forma operating profit for its financial year to 31 October 2011 of £3.2 million on a turnover of £16.3 million.
Paul Pindar, chief executive of Capita, said, "Expotel will bring both significant additional expertise and greater scale to our UK-focused corporate travel business."
Pindar said Expotel combined with its existing travel business would employ nearly 900 staff in ten locations. "With the public sector needing to drive down travel and subsistence costs, the business will be in a strong position to help local and central government achieve these aims," said Pindar.
John O'Brien, an analyst at TechMarketView, said, "Pindar is focusing his attention on the company's true knitting, IT-enabled business process services.
"In the public sector in particular there should be plenty of potential to drive out cost from travel and venue hiring."
Capita also acquired business travel firm BSI Holdings in December 2010, which provides travel services for Marks and Spencer, EasyJet and the Crown Prosecution Service.
Earlier this week it was reported that Mark Quartermaine, recruited just six months ago as managing director of Capita's newly created IT Services operation, had to join Juniper Networks as UK head of operations.