FRANK Lloyd Wright, America's greatest architect, borrowed from an unbuilt design by Charles Rennie Mackintosh for one of his most famous buildings in the US, according to a newly discovered eye-witness account.

Wright, one of the most important and influential of modern architects, built the Annunciation Greek Orthodox Church in Milwaukee, Wisconsin in the late 1950s.

It was one of his last major commissions. Wright - a contemporary of Mackintosh - died in 1959 before the dedication of the church in 1961.

However, the extraordinary flying-saucer shape of the church was directly inspired by an unbuilt concert hall designed by Scotland's most famous architect, according to Cemal Ozturk, one of Britain's leading architectural model makers.

The concert hall design by Mackintosh, which was designed in 1898 and features a huge dome that also looks remarkably similar to the Millennium Dome built 100 years later, was to be built in Kelvingrove Park in Glasgow but never made the transition from drawing board to reality.

Mr Ozturk yesterday opened an exhibition, called Unbuilt Mackintosh: The Models, at Keppie Design in Glasgow that will run until June 22. Mackintosh was a partner at the firm from 1902 to 1913.

Researching the history of the designs in the exhibition, Mr Ozturk came across quotes by Thomas Howarth, a former teacher at the Glasgow School of Art who was a pivotal figure in re-establishing Mackintosh as an architect and designer

of note.

Mr Howarth's eye-witness report of how Wright was ''inspired'' by the Mackintosh design proved to be fascinating, Mr Ozturk said.

''Wright was definitely influenced by Mackintosh. If you look at his church in Milwaukee, the top half is Mackintosh and the bottom half is Wright,'' he said last night.

''No-one had designed such a long shallow dome as that before Rennie Mackintosh: Wright saw what he had done and within a few days the church was designed.''

Mr Howarth, who in 1952 published an influential book, Charles Rennie Mackintosh and the Modern Movement, that helped to revive the Glasgow artist's reputation, later went on a research trip to America and met Wright.

He was given a tour of the architect's studios at Taliesin West, Arizona, and showed him the work of Mackintosh, including some unbuilt designs.

Mr Howarth later wrote: ''I kept an eye on Wright and noticed the special attention he paid to a photograph of Mackintosh's competition entry for an international exhibition centre for Glasgow in 1901.''

On the day Mr Howarth was to leave, he called into Wright's office and was called by the architect over to his desk. He had begun work designing the church.

Mr Howarth wrote: ''He was ablaze with creative excitement but I was immediately embarrassed - I didn't know what to say - because the emerging design was so much like the Mackintosh international exhibition design that he had been studying over the preceding days. I found myself saying: 'It's a great drawing, it has Byzantine features, but it's also remarkably like Mackintosh's exhibition hall.'

''He looked at me, gave a little cough in his hand, looked at the drawing, then sat down and got on with his work. As I turned away he smiled.''

Other buildings in the exhibition include a science and

art museum and a railway

terminus.

The domed concert hall, which could have held 4000 people, would have been dominated by its clear roof span of 55 metres, although it is unclear from Mackintosh's design how it would have been engineered.

Mr Ozturk said that in the 50 years between Mackintosh's design and Wright's church, concrete construction technology had advanced so that a low, slim dome became possible to build.

Mr Howarth also believed that another work of Wright's, the dome over the Marin County Civic Centre, from 1957, was inspired by the same Mackintosh design.

Mr Howarth designed the first major exhibition of Mackintosh for the Scottish Arts Council in 1953 and also staged exhibitions in Canada and Washington DC. He died in 2000.

The models in the new exhibition, which have taken two years to build, are the first Mackintosh designs to be built since the opening of the House for an Art Lover. Designed in 1901, it was erected in Glasgow's Bellahouston Park between 1989 and 1996.

style and substance

Frank Lloyd Wright was born in Richland Centre, Wisconsin on June 8, 1867 and died on April 9, 1959 - he worked right up until his death.

Regarded as one of the most important figures in modern architecture, he developed a building style based on natural forms, which he called ''organic architecture''.

He was known for buildings based around the shapes of plants, trees, and rock formations.

He proposed using reinforced concrete in the patterns found in seashells and snails, and would build skyscrapers based on trees - a central trunk deeply rooted in the ground.

Wright's entire career was a struggle. He was written off a number of times, and many of his later works were extremely controversial, such as the Marin County Civic Centre, his 770th commission.

He is regarded by many architectural experts as a bona fide genius, and has been an influence on generations of architects and designers.