The area of Salthouse marshes which is on the market.

A stretch of north Norfolk’s wild coastline is up for sale with a £1.2m-plus price tag, and several would-be buyers are said to be interested.

About 58 hectares (143 acres) of Salthouse marshes has been put on the market, including grazing marshes, reed beds, freshwater and saline ponds.

Agents Strutt and Parker, who are handling the private treaty sale on behalf of the vendor, said there had already been a great deal of interest from organisations, individuals and agents, locally and from London.

Both the National Trust and Norfolk Wildlife Trust (NWT) own sites adjoining the stretch. NWT is understood to be interested in buying the land. The National Trust is keeping its cards close to its chest.

Russell de Beer, of Strutt and Parker, said the owner, who had a shooting syndicate business on the land, wanted to retire.

The site is being marketed as “A fantastic and unique opportunity to acquire some of the best sporting and wildlife coastal marshes in Norfolk.”

It lies off the A149, between the NWT’s Cley Marshes reserve to its north, and the National Trust’s Granborough Hill, to the south.

The sale site is covered by the designations: Nitrate Vulnerable Zone, Biosphere Reserve, Special Site of Scientific Interest, Ramsar Site, Special Protection Area, Area of Outstanding Natural Beauty and part is an Area of Conservation.

Dr Tony Leech, chairman of the North Norfolk branch of the NWT, said the sale was an opportunity to bring a long run of important, undeveloped coastline, stretching north to the National Trust’s Blakeney National Nature Reserve, under conservation management.

Sophie Barker, warden with the Norfolk Ornithologists’ Association, said if the marshes were bought by either the NWT or National Trust it would ensure their long-term future for the conservation of wildlife and would be “totally in keeping with the surrounding area.” Ms Barker added that any wetland habitat was very important for waders and wildfowl in particular.

A National Trust spokesman said: “From time to time the National Trust acquires new land as part of our mission to protect our country’s most beautiful places for ever, for everyone.

“We are aware of the land for sale at Salthouse marshes and we are currently considering our position.”