The owner of the high street chain Phones4u is closing in on a bumper takeover of Cartrawler, the owner of the Holiday Autos car rental brand.
Sky News understands that BC Partners, one of the UK's leading private equity firms, has seen off competition for Cartrawler from rivals Berkshire Partners and Charterhouse, to win a period of exclusivity in which to finalise the deal.
A transaction, which would be valued at well over £300m, could be signed as soon as Friday and would represent a higher-than-expected sale price, sources said.
ECI Partners, the firm which owns a controlling stake in Cartrawler, a Dublin-based provider of online car rental distribution systems, appointed PricewaterhouseCoopers (PwC) to run an auction last year.
A sale of Cartrawler, little more than two years after it last changed hands for about £80m, would come as private equity firms attempt to exploit strong demand from rivals to deploy a vast wall of capital accumulated in recent years.
The previous takeover of Cartrawler earned multimillion pound windfalls for Greg and Niall Turley, the brothers who founded the business and oversaw its expansion into more than 170 countries.
CarTrawler announced the acquisition of the online assets of Holiday Assets last summer, buying them from Travelocity Global, the immediate parent company of Lastminute.com, the online leisure bookings company.
That deal reunited ECI with Holiday Autos, which it had owned for several years before selling to Lastminute while it was a publicly-listed company in London in 2003.
CarTrawler, which has become a popular platform for companies to rent cars online, has annual bookings of around 5m vehicles, and sales of more than £425m.
Advent International, Kohlberg Kravis Roberts (KKR) and Montagu Private Equity were among the other buyout firms which expressed an interest in buying Cartrawler earlier in the process.
BC and ECI declined to comment.