An Icelandic artist - whose previous work has included turning a river green and suspending a lawn from the outside wall of a gallery - will be the next to exhibit in the Tate Modern's Turbine Hall.

Olafur Eliasson will undertake the fourth in The Unilever Series of commissions for the hall.

Turner Prize winner Anish Kapoor's work Marsyas - at 10 storeys high, one of the world's largest indoor sculptures - is currently on display.

Eliasson - whose work will be displayed between 8 October next year and 21 March 2004 - was in London on Tuesday to explore the Tate's space.

Casting his eye across the hall, he spoke of creating a work that reflected its former use - "the idea of energy being a source of fuel, of a Utopic vision at the beginning of the century".

Juan Munoz exhibited in the Turbine Hall in 2001

Eliasson, who lives and works in Berlin, has become known for his installations and sculptures which often feature light, water, steam and fire.

In 2000 he turned a river in the city of Stockholm luminous green using pigment developed by marine biologists for measuring the turbulence in water.

He said his aim was to "challenge the viewer's knowledge of the natural landscape".

Eliasson has participated in numerous exhibitions worldwide, though this marks his first large exhibition in the UK.

'Delighted'

Previous works have seen him create artificial geysers and rainbows in galleries, using steam and light.

In 2000, at the Bonakdar Gallery in New York, Eliasson used mirrors to expand the gallery's interior.

He also suspended a 20ft lawn outside the second floor of a Chicago gallery. Visitors could only stare at it through a window.

A spokesman for the Tate Modern said gallery bosses were "delighted" with Eliasson's appointment.

He added that no-one at the gallery had "any idea" what form the exhibit would take.

Unilever's financial support, which totals �1.25m over five years, will allow the Tate Modern to commission a new work for the Turbine Hall each year until 2004.

Previous commissions in the series have been completed by the French-American artist Louise Bourgeois and Spanish artist Juan Munoz.