Plans to build a roof over the main swimming pool for the Olympics have been abandoned because it would not be finished in time for the start of the Games in August, Athens Olympics organisers said on Saturday.

Organisers said work on the roof for the outdoor pool was stopped after consulting with the International Olympic Committee (IOC) and the International Swimming Federation (FINA).

"We have come to the conclusion that the timely completion of the roof was not guaranteed and this could jeopardise the running of the competitions," Athens organisers said in a statement.

"The IOC has been informed and immediately asked the Greek government and ATHOC to work on contingency plans...to ensure there will be no negative effects for athletes, the sport and broadcasters," it said.

The roof had been planned to shade swimmers from Athens' searing summer temperatures and allow high-quality broadcasting of events.

While the roof was not an Olympics-related project, it was important for broadcasters because swimming and water polo competitions have been scheduled for midday when the light is brightest.

But according to officials, the swimming events were likely to be shifted to early morning and late afternoon to avoid direct sunlight hitting the pool allowing athletes to compete in cooler temperatures.

"We are very relieved and so is the IOC and the government with this decision," an ATHOC source told Reuters, adding that organisers would now increase lighting around the pool for the afternoon competitions and add temporary shading above the grandstands.

"PERSONAL DECISION"

"It was a personal decision by the Prime Minister Costas Karamanlis after being briefed by ATHOC and the IOC. It was a tough decision to make," the source said.

Athens will hold the first outdoor swimming events since the 1992 Games in Barcelona.

The decision to scrap the roof is the third major shift in organisers' plans since a conservative government came to power in the March 7 election, ending more than a decade of socialist rule.

"Seven years after winning the bid and less than 150 days before the start of the Games there are still pending issues," Karamanlis told Parliament on Saturday. "But we are enforcing new, intensive rhythms...and despite delays we are certain we will organise a successful Games."

Since Karamanlis came to power, landscaping for the start of the marathon has been trimmed and the transport ministry has scaled down building of a rail line linking the nearby port of Piraeus to central Athens.

The actions to get the Games ready in time were part of the "tough decisions" that IOC chief Jacques Rogge demanded when he met Karamanlis a week ago.

"This was a wise decision which frees us from more serious problems we could have faced in the coming months if work on the roof started," ATHOC spokesman Serafim Kotrotsos told Reuters.

More than half of the venues are not finished, including the main Olympic stadium which will not be ready until three weeks before Games start on August 13.