WORK to create a new £49m exhibition centre at the Ashmolean Museum has begun.

The new building, which will replace a 19th-century extension, will double the gallery space and have environmental controls for delicate artefacts.

Museum spokesman Susie Gault said the work would be completed by 2009. The Ashmolean, in Beaumont Street, dates back to 1683.

Ms Gault said the new space would allow thousands of objects previously held in storage to be displayed for the first time.

The main part of the museum will remain open during the work.

Dr Christopher Brown, the Ashmolean's director, said: "The plan will ensure not just the creation of a landmark building, but also an enriched future for the museum's collections and visitors."

Foundation work for the new building will begin in May.

The total cost of the project is £49m, of which £41m has been raised through the support of trusts, foundations, individuals and the Heritage Lottery Fund.

The plan will include an education centre, with teaching rooms and study centres, and state-of-the-art conservation studios. Greek and Roman collections, currently split between two sites, will be integrated.