Carlyle Group LP, Permira Holdings Ltd., Onex Corp., Apax Partners LLP and Cinven Partners LLP are concerned that the city of Rome's plan to close shops on Sundays could derail their pursuits to acquire Italian restaurant chain Old Wild West, Reuters reported, citing undisclosed sources.

The private equity firms submitted indicative bids in advance of the Oct. 15 deadline, two of the sources told the news outlet. Sources said the suitors valued the steakhouse chain at more than €700 million, with some buyout offers exceeding €750 million.

However, a proposal by Italy's Deputy Prime Minister Luigi Di Maio to ban Sunday shopping in large commercial centers before the end of 2018, could hit the restaurant chain's performance and undermine a potential sale, the sources added.

BC Partners, which bought out Old Wild West holding company Cigierre in 2016, employed Rothschild and JPMorgan earlier in 2018 to find a buyer, Reuters noted, citing the sources.

BC Partners is likely to shortlist potential buyers for the final round of the sale by Oct. 20, the sources told Reuters.

BC Partners, Cinven, Carlyle and Onex did not comment on the matter. Apax was not immediately available when asked for comment.