ONE of the world’s most iconic steam locos is to leave York after 35 years at the National Railway Museum.

The Mallard, which broke the world steam speed record in 1938 when it reached 126mph, is to move in June to Locomotion, the NRM’s sister museum in Shildon, County Durham.

NRM director Steve Davies said the famous blue loco had been a favourite with visitors since 1975.

He said: “But now we think it’s time to share one of the jewels in our crown with our sister museum.”

The space currently occupied by Mallard will be taken by South Eastern & Chatham Railway steam locomotive No.737 and Pullman Car Company First Class carriage Topaz.

“We haven’t decided when Mallard will return to York, but in the meantime we’re sure that our visitors will enjoy No.737’s elaborate livery and the luxurious look of Topaz,” he said.

Durham councillor Eunice Huntington, who sits on Locomotion’s board, said it was going to be home to Mallard “for the foreseeable future.”

Gillian Cruddas, chief executive of Visit York, said it would be “sad” to see it move from York.

“It is an iconic train in the fantastic collection at the National Railway Museum.

“We hope, however, that by showcasing the train up in County Durham, we can encourage more visitors to visit York to experience both the city and the world-class collection of trains here. We hope too to see the Mallard back in the future.”

The Mallard will be pulled to Locomotion by Tornado, the new steam locomotive built over almost 20 years by The A1 Steam Locomotive Trust in Darlington.

• The Mallard will be given the send-off it deserves when in the Spring Bank Holiday half-term 2010, the NRM puts on a range of festivities to wish it a fond farewell, before it leaves on June 23.