Private equity group Isis is close to hiring DC Advisory, the corporate finance advisory firm, to search for a new investor, The Sunday Times reported.
Analysts have said the website could fetch up to £100m. It is thought to have made earnings before interest, tax and other charges of around £10m in the year to September.
The Manchester-based company, which employs around 200 staff, offers flights, accommodation, beach holidays in Europe, North Africa, the Caribbean and central America as well as currency, insurance and car hire services.
Founded in 2004 by Simon Cooper, 40, from his house in Macclesfield the website arranged beach holidays for consumers via teletext and a small call centre.
The business grew rapidly and in 2007 Cooper sold a stake in the firm to Isis while keeping his role as chief executive and a significant shareholding in the company.
Cooper previously founded a niche tour operator in 1995 called On the Piste, that provided cheap ski holidays to students.
Isis backs a number of retail companies including Crew Clothing, Fat Face and bought a £5.2m stake in Vietnamese noodle chain Pho in July. It sold Wiggle, the online cycling retailer, to Bridgepoint last year for £180m.