On the Beach may be snapped for about £75 million by the buyout firm behind Jack Wills clothing stores.
The Sunday Times reports Inflexion has entered exclusive talks to buy the online agency, which was founded by Simon Cooper, 41, from a house in Macclesfield.
A sale would generate a profit for Isis, a rival buyout firm, which has backed On the Beach for six years allowing it to invest heavily in technology.
Before launching On the Beach, Cooper ran ski site On the Piste, which he sold to Tui Travel.
On the Beach employs about 200 staff and handles 750,000 travellers a year.
In June, On the Beach hired corporate finance house DC Advisory to help it find new investors, see previous story.
