Young's Seafood, owners of the threatened Cromer Crab Company, could be put up for sale and some sites closed, it has emerged.

Young's is part of the loss-making Findus Group whose owner Lion Capital has appointed advisors to evaluate Young's and The Seafood Company - also under the Findus umbrella - in a bid to cut the group's debts.

The two businesses employ about 3,200 people across 13 UK sites, including 230 involved in shellfish processing at Cromer. A sale of the two could raise up to �450m, according to the Mail on Sunday.

Options being considered include closing certain sites - news likely to increase concern among Cromer campaigners who are due to hand over a 6,000-plus signature petition to Young's bosses at the Holt Road factory tomorrow morning.

They are calling on Young's to reconsider plans which could see the site closed and production moved to Grimsby or Scotland.

The latest revelation is likely to give added urgency to North Norfolk MP Norman Lamb's forthcoming meeting with Lion Capital, a London-based private equity firm.

He wrote asking the firm to host a delegation of town and district council representatives and has heard from Lion partner Ken Smialek who is seeking to arrange a date. Supporters hope to persuade owners that the Cromer crab brand is a potential goldmine if its name is protected and production remains in the town.

The Labour-led petition will be handed over by representatives from all the major parties in a show of unity against the prospect of what is widely seen as a potentially-devastating blow to the town and its economy.

Lion Capital bought Findus in 2008 for �1.1 billion, but it has faced rising competition and costs in the fish market.

The group came close to breaching the covenants on its �721 million debts earlier this year because of the tough markets both for fish and other frozen food but renegotiated its terms with more support from Lion Capital.

Findus made a net loss of �151.6 million in its last financial year after hefty interest charges.