A number of private equity groups are circling Costa, opening the door to a potential £3bn sale of the business, according to reports.
The Press Association has reported that parent company, Whitbread, which last month announced it was working towards a demerger of the coffee chain, has been approached informally over a potential buyout of the firm.
Those thought to be considering a move on Costa include Bain Capital, CVC and TPG, people with knowledge of the matter told PA
Whitbread is pressing ahead with plans to spin off Costa in a separate listed company within the next two years, but a private bid for the group, which is valued at £2bn to £3bn, would have to be considered by the board.
Costa, which Whitbread acquired in 1995 from founders Sergio and Bruno Costa, has more than 2,400 stores and is embarking on overseas expansion.
It is thought that a private buyer would continue the expansion and tighten up costs at the group.
In April, Whitbread announced its proposals for Costa following pressure from activist investor Elliott.