Swimming's world governing body said on Monday it was greatly disappointed that plans for a roof over the main Olympic swimming venue had been scrapped.

Under-pressure organisers of the Athens Games said on Saturday they had abandoned plans to build a roof above the outdoor pool because there was not enough time to finish it before the event starts in August.

The sport's ruling body voiced disappointment on Monday, saying it had been guaranteed the temporary roof would be built and that it was "essential" to protect competitors and spectators from the searing Greek sun.

"FINA would like to remind that one of its recommendations in the bidding documents for the Olympic Games stipulates the preference for the competition to take place in an indoor venue," a statement said.

"As this solution was not possible, FINA and (Games organisers) ATHOC decided to construct a temporary roof, as done for the 1996 Olympic Games in Atlanta."

FINA said that dating back to 2001, it had received guarantees that the roof would be constructed and that this month -- just before the general election -- former Greek Deputy Minister of Culture Nassos Alevras had reiterated a guarantee that it would be ready by July 15, 2004.

"To FINA's total surprise, it was now announced that the construction of the roof will not take place," the statement added.

"This structure was essential to protect from the sun and the high temperatures the swimmers, water polo players, officials, media representatives and spectators, and to create the best possible Olympic swimming competition environment.

"Moreover, it was an important requirement to assure the optimal conditions for the Olympic TV production.

"FINA regrets very much this decision, which does not respect any of the previous agreements."

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

The decision to scrap the roof is the third major shift in organisers' plans since a new conservative government ended more than a decade of socialist rule by winning a March 7 election.

Landscaping for the start of the marathon has also 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 on time were part of the "tough decisions" that IOC chief Jacques Rogge demanded when he met new Greek Prime Minster Costas Karamanlis a week ago.