EAT, the sandwich bar chain, will announce plans to double in size to at least 100 shops today after completing a £39 million refinancing with the private equity firm Penta Capital, The Times has learnt.

Penta, which recently floated La Tasca, the tapas bar operator, is buying the 42 per cent stake held by 3i while Barclays Bank is providing £18 million in new debt funding.

The deal, which is believed to value EAT at between £20 million and £25 million, will see Penta end up with a 45 per cent stake. Niall MacArthur, the founder, is raising his stake to a similar level after increasing the amount he has invested in EAT to more than £1 million.

Mr MacArthur, who will remain managing director, launched a review of the business in April, appointing Altium Capital to advise on the process. An initial public offering was among the options considered.

The entrepreneur founded the business in 1996 with his wife, Faith, opening the first shop in Villiers Street, Central London. It now has 45 shops, of which 35 are in the capital, serving 200,000 customers a week.

Mr MacArthur said last night that the new funding was designed to allow the group to reach 100 shops within the next three years, of which about two thirds would be in London. It has two shops in Manchester and is about to open a third there.

Mr MacArthur said: “We felt we needed a more aggressive and supportive venture capitalist to reach our targets. At that point an initial public offering would be one of the options available to us.”

Its central kitchen in Wembley, where 130 staff prepare all of its food freshly every day, will take on another 40 staff to handle the projected growth.