OXFORD'S first rooftop cafe will be one of a number of new attractions at the Ashmolean following the museum's major redevelop- ment.

The initial stage of construction work for the new extension of the prestigious Beaumont Street museum was completed on Monday.

In a ceremony to mark the latest stage in the building project, Dr John Hood, vice-chancellor of Oxford University, and Richard Gregory, of the construction group HBG UK Ltd, poured concrete into the highest section of the new building.

The extension will provide 100 per cent more display space, allowing thousands of objects previously in storage to be shown for the first time.

The development features 39 new galleries, a new education centre, state-of-the-art conservation studios, and a walk-through between the museum and the cast gallery. It is due to open next year.

James Purnell, former Secretary of State for Culture, Media and Sport, said: "When the development is complete, and the expanded museum opens in Autumn 2009, visitors will be provided with a world-class museum to match the Ashmolean's world-class collections."

Throughout this year, the new galleries will be fitted out in preparation for the installation of custom-made show cases and exhibition displays.

The Heritage Lottery Fund has awarded the scheme a grant of £15m.

Additional support has been raised by the leading private donor, the Linbury Trust, along with numerous trusts, foundations and individuals, towards the total project cost of £61m.

Founded in 1683, the Ashmolean is the most important museum of art and archaeology outside London and its collections cover a wide range of cultures from early Egyptian to Italian Renaissance, and 20th century European art.

Among its treasures are Guy Fawkes's lantern, the largest and most important collection of Raphael drawings in the world, the most important collection of pre-Dynastic Egyptian material outside Cairo, and the greatest Anglo-Saxon collections outside the British Museum.

During the Ashmolean's redevelopment, the museum remains open to the public.