The winner of a children's art competition being run by Oxford's Ashmolean Museum will have their work paraded across the city for thousands to see.

But there will not be a giant canvas or huge exhibition - the winning artwork will appear on the back of two Oxford buses.

The museum has launched the competition, called Picturing the New Ashmolean, for four to 16-year-olds, and laid down a challenge for them to create a colourful, bold and eye-catching image relating to the museum.

The museum is currently undergoing redevelopment, which is due to be opened to the public in autumn 2009, complete with 39 new galleries.

The competition's lead sponsor, the Oxford Bus Company, will parade the winning artwork on the back of Oxford park-and-ride buses throughout the city during 2008.

Ashmolean director Christopher Brown said: "We're extremely grateful to all the sponsors of this competition.

"With their help we can give young people from Oxfordshire and the surrounding counties the opportunity to create and publicly exhibit their vision of the new Ashmolean."

Philip Kirk, managing director of the Oxford Bus Company, said: "People often talk about the back of a bus.

"Now youngsters can win the chance to see their artwork there."

To inspire youngsters who might be thinking of putting pen - or paints - to paper to enter the competition, a series of activities is being held at and around the museum.

These include the Ashmolean's activity trolley, hard hat tours of the construction site and a Big Draw workshop with Korky Paul, best known for his illustrations in the Winnie the Witch series.

Mr Paul said: "This is all about getting children to picture the magnificent, marvellous and magical new Ashmolean in 2009."

Entries will be divided into three age-groups: Four to seven, eight to 11 and 12 to 16. The competition is free to enter and the closing date is October 31. A panel of judges will select three winners from each category and prizes include computers, Korky Paul books and gift vouchers.