Blackstone said yesterday it would continue Antares' refurbishment of local Burger King restaurants and also plans to add new branches.
Senior managing director Peter Rose could not give specifics on the expansion but said the company was "very optimistic and very encouraged" by the possibilities for growth.
Although this is believed to be Blackstone's first involvement with Burger King, Rose said the group had experience owning and operating food businesses in Britain.
Speaking from New York, Rose said Blackstone was drawn to Antares' "world-class" management team.
"Burger King is an iconic franchise and obviously world-renowned but as with all retail and personal-services businesses management is the key and with the management here we saw just a world-class team," he said.
Antares' management team will stay on.
Antares chief executive John Elliott said Blackstone "was the perfect partner" to take the company to the next level.
Anchorage Capital partner Mark Bayliss said Antares was sold because the private equity fund had "done its bit" and breathed new life into the firm.
"[Anchorage] turns around underperforming businesses, when we've put businesses on a sustainable growth platform we hand it on to someone who can take it through a growth phase. We bought an inherently good business, changed some of the management team and we've transformed every single aspect of the business, financially, operationally and strategically," Bayliss said.
A Burger King spokeswoman said last week the Rugby World Cup had had a positive impact on the fast food chain's sales.