The tower hit problems not long after opening

Officials said that the 100-metre structure is expected to be open to the public in "late summer".

The disclosure came as the Princess Royal visited the �75m centre, which was opened by the Queen in 2001.

The tower, which is designed to rotate with the wind, opened four months later, but had to close within months.

The futuristic-looking complex, built on a derelict site beside the River Clyde, has been visited by more than one million people, however, it has faced problems.

New bearing

Staff have also faced job losses and at the end of June the centre said it was to make about a fifth of its workforce redundant.

The tower, which was designed to mark the Millennium, shut for repairs in February 2002.

It closed after it was found to have sunk because of damage to two bearings in the rotating base mechanism.

Princess Anne visited the centre

Centre chief executive Brian Weddell said a new bearing had been installed and was now being tested ahead of the reopening.

"The princess was delighted to hear it would be reopening," said Mr Weddell, who declined to give a precise date.

Princess Anne began her visit to the centre by meeting more than 20 primary school children from the south of Scotland who are undertaking research for the American Space Agency Nasa.

The primary six and primary seven youngsters from Dalry Primary in Dumfries and Galloway take regular weather readings as part of an international project on global warming.

Teacher Catriona McCall said: "They were very excited to be here, as other schools are doing this but they were the only school invited.