Sky News has learnt that Wheel Topco, which owns PizzaExpress Group, lodged the idea of a combination with The Restaurant Group's (TRG) board several months ago.

As part of the deal, Wheel's shareholders would have taken a sizeable equity stake in TRG if a transaction had been agreed.

City sources said that PizzaExpress was now working with Goldman Sachs on its interest in TRG, which could lead to it making an offer for the company.

TRG, which also owns the Brunning & Price pub chain, confirmed last week that it had received renewed contact from Wheel following a report by Sky News.

In a stock exchange statement, the Wagamama-owner said it had "received a request within the last week from Wheel Topco…for diligence information on the company…to enable Wheel Topco to evaluate a possible offer for the company".

"No written or verbal indicative proposal relating to a possible offer, including as to terms, price or form of consideration, has been made to the Board of TRG by Wheel Topco," it added.

PizzaExpress's owner has yet to make a public statement about its potential interest, while the earlier proposal has not been disclosed by either party.

Earlier this month, TRG agreed to be bought by Apollo Global Management for just over £500m.

PizzaExpress is controlled by a group of debt funds including Bain Capital Credit and Cyrus Capital Partners, which took ownership in 2020.

Prior to that, the UK's biggest chain of pizza restaurants was owned by China's Hony Capital.

Allan Leighton, PizzaExpress's chairman, previously chaired Wagamama during its ownership by the private equity firm Duke Street, and engineered its sale to TRG in 2018.

He then spent a brief period on TRG's board.

Under the terms of Apollo's 65p-a-share offer, a rival bid would need to be at least 10% richer for irrevocable shareholder undertakings to lapse.

Oasis Management, an activist hedge fund which had pressed for boardroom and strategic changes at TRG for months, has said it will vote its near-18% stake in favour of the deal.

It was unclear at what price PizzaExpress might contemplate bidding, or how it would finance an offer.

Last month, TRG announced the sale of Chiquito's and Frankie and Benny's, two of Britain's best-known casual dining chains, to The Big Table, another restaurant operator.

That deal saw The Big Table, which is backed by the buyout firm Epiris, adding the two brands to a portfolio which includes Amalfi, Banana Tree, Bella Italia, Cafe Rouge and Las Iguanas.

TRG declined to comment, while Wheel Topco could not be reached for comment.

Goldman Sachs also declined to comment.