Forecourt retailer EuroGarages has secured the backing of investment firm TDR Capital, which also backs Stonegate Pub Company, in a deal which values the business at £1.3bn.
Founding family members Mohsin and Zuber Issa will continue to run the group, which has a portfolio of more than 340 sites, and remain majority shareholders.
It currently manages sites under BP, Esso and Shell fuel brands and has developed partnerships with brands such as Starbucks, Subway, Burger King, Spar and Greggs.
TDR currently owns rival European Forecourt Retail Group (EFR) and it is understood that it is exploring options to combine the businesses ahead of an IPO.
Founded in 2001, Blackburn-headquartered Euro Garages has grown from a single site in Bury in the North of England to become one of the largest independent forecourt operators in the UK.
Revenues increased 47% to £646m in the year to 31 July 2014, while profits climbed 67% to £30m.
The business secured a £100m-plus finance package in July to support its latest acquisitions, which included more than 170 Esso and Shell sites.
Mohsin Issa said: “Over 15 years we have built our business and a strong position in the UK forecourt retail market with our superior customer offer supported by partnerships with leading convenience and food-to-go brands. TDR understand our business and have significant experience in our sector so are the perfect investment partner as we continue to develop our proposition.
“This is an exciting new phase for the business and we look forward to working with TDR to grow our business further in the UK and internationally.”