The agency beat WCRS and Brooklyn Brothers to the account, in a pitch handled by OysterCatchers. Farm, the incumbent on Lastminute.com, was not involved in the process.
In the past, Travelocity has used Miles Calcraft Briginshaw Duffy to produce its advertising, but has not run any significant campaigns since 2005.
Karmarama will work across all three brands and has been briefed to produce work that will break early next year. Lastminute.com said it plans to spend £10 million on advertising in the UK this year, but it is expected that the combined account will be larger, as Sabre Holdings, the travel company's parent, looks to boost spend on the other travel brands.
Julie Davidson, the Lastminute.com UK marketing director, said: "Karmarama delivered a strong strategic vision and displayed creative thinking."