The Natural History Museum has announced that Scandinavian architects CF Møller and Partners will design phase two of the museum's new Darwin Centre.

The Darwin Centre is a multi-million pound project to reveal for the first time 80 per cent of the museum's collection of more than 70 million specimens.

Phase two, which is expected to cost around £50m, will house 28 million insects and six million plant specimens. The design, a cocoon-like building encased in a transparent outer structure, was chosen from 59 design teams through an architectural competition.

It will sit alongside the £27m phase one, designed by HOK International, which opens to the public in September 2002 and contains the museum's 22 million zoological specimens stored in alcohol - the Spirit Collection. The Darwin Centre will also provide state-of-the-art facilities for nearly 300 scientists who work at the museum.

Phase One was funded with money raised by the Natural History Museum's Development Office. The Heritage Lottery Fund has earmarked nearly £15m towards the construction of phase two, and the museum is involved in a fundraising campaign, which has already raised £27m towards the total costs.

Both of the new buildings will sit alongside the original museum, which opened in 1881.

With the Millennium ushering in a new age of scientific discovery, The Darwin Centre will enable people of all ages and nationalities to get 'under the skin' of real science and access inspirational, high quality information about the natural world, said director of The Natural History Museum, Sir Neil Chalmers.

The Darwin Centre phase two is expected to open in 2007.