The Olympic Stadium is seen after the last piece of turf was laid on its field of play, in London, March 29, 2011. London hosts the Olympic Games from July 27 to Aug 12, 2012. [Photo/Agencies]

LONDON - Construction on the flagship stadium for the 2012 London Olympics was completed Tuesday when the last patch of turf was laid on the grass infield of the 80,000-seat venue.

The $777 million Olympic Stadium was finished under budget and three months ahead of schedule - less than three years after work began in May 2008 and 16 months before the opening ceremony on July 27, 2012.

"In some previous games we were struggling to have a stadium ready for the opening," IOC executive board member Denis Oswald said. "Here, more than a year ahead of the games, now it's ready and we could nearly compete tomorrow. This is very encouraging and very satisfactory."

The stadium, which will host the track and field competition and opening and closing ceremonies, is the centerpiece of the overall $14.8 billion project, which is transforming a former industrial wasteland in east London into a massive Olympic Park.

Former Olympic sprinter Frank Fredericks used a shovel to put down the symbolic last patch of grass on the 97,000-square foot infield, as London organizing committee chairman Sebastian Coe and others stood by.

The surface of the running track will be installed this year, while organizers will also need to dress up the stadium and prepare 700 rooms and other facilities.

"We wouldn't want anyone to run away with the idea that this stadium is ready to stage an Olympic track and field championship tomorrow," Coe said. "But as chairman of an organizing committee, to be able to tick off structurally these venues is terrific. With one year and a few months to go, this is a great place to be."

Oswald heads the IOC coordination commission for London, which is making its eighth visit to the city to check on preparations. Fredericks, a Namibian sprinter who won four Olympic silver medals, is one of the commission members.

"They have lived up to the promises of building a fantastic facility," Fredericks said, standing a few yards from the finish line. "It's also good that they are sending out a positive message that it is possible to do this under budget."

After the games, the stadium will be converted to a 60,000-seat venue that will serve as home to West Ham soccer team. The arena will also host track and field competitions, concerts and community events.

West Ham was selected over a bid from Premier League rival Tottenham, which proposed building a soccer-only stadium on the site without the track.

"You don't know how many votes London got because they promised a legacy in the track," Fredericks said. "It's nice that they kept their promises."

A light rain was falling at the stadium before the sun came out as IOC officials and organizers arrived for the occasion. The stadium roof only partially covers the stands, meaning spectators may have to contend with London's traditional wet weather during the games.

Olympic Delivery Authority chairman John Armitt said building a roof covering all the seats would have added "a lot of money".

"As always, these things are a compromise," he said. "We've got about two-thirds of the spectators covered. Basically it's a summer stadium for the games. I think it will work. If you're bound up with the excitement of an Olympic Games, a light shower is not going to put anybody off."

The IOC commission is in town amid a messy legal dispute between Coe's organizing committee, LOCOG, and the British Olympic Association. The BOA has taken LOGOG to the Court of Arbitration for Sport, claiming that it deserves a larger share of any surplus generated by the games.

Oswald, who has urged the BOA to drop its case, said he hopes the issue can be resolved this week.

"The sooner, the better," he said. "We hope everybody will concentrate on the success of the games and not on a dispute which does not help either party."