A fast-growing firm which rents out holiday properties has been taken over by a major American company.

Holiday Lettings based in Summertown, Oxford has been bought for an undisclosed sum by travel website TripAdvisor.

The move is a major development for Holiday Lettings founders Ross Elder and Andy Firth, who have grown the business from buying the domain name on the Internet in 1999 to an operation which now has an annual turnover of more than £5.5m.

Mr Elder said: “The combination of our holiday home marketing expertise with TripAdvisor’s leadership in the travel community is a natural fit.”

Managing director Mr Elder and technical director Mr Firth will continue to run the business which has doubled in size from 40 staff to 80 in the last two years.

It currently advertises more than 40,000 holiday homes in 116 countries on behalf of private owners, property managers and letting agents.

Company spokesman Kate Stinchcombe-Gillies added: “TripAdvisor has entered this market to learn from us and grow the business.”

Mr Elder and Mr Firth sold two thirds of the business to property website Rightmove in 2007 but TripAdvisor has bought the whole of the company taking its portfolio of travel brands to 17.

Steve Kaufer, founder and chief executive of TripAdvisor, said: “Our acquisition of Holiday Lettings significantly enhances the choice of fantastic holiday homes available to the TripAdvisor community, particularly within Europe.

“It will also enable travellers to benefit from a wealth of destination information from fellow travellers to help them plan their perfect trip.”