JOHANNESBURG — Construction of one of South Africa's 2010 World Cup stadiums will miss its completion deadline after hundreds of workers were fired for going on an illegal strike, a spokesman for the contractor said Thursday.

The delay comes ahead of Friday's start of ticket sales for the event, which is being held in Africa for the first time.

Eugene du Toit, spokesman for the Mbombela Stadium Joint Venture, said the stadium in the eastern town of Nelspruit would not be completed by April as planned. Instead it would now be finished toward the end of the year, six months before South Africa is to stage the event.

No comment was immediately available from FIFA.

Stadium construction in South Africa has been plagued by delays and industrial unrest. But initial fears that the venues would not be ready in time have eased as most building is on schedule.

Du Toit, from Basil Read construction company, said about 400 workers were dismissed on Monday after violating an agreement preventing them from striking.

"As a contractor, it has been quite a setback," he said.

Du Toit said police were at the site and construction had resumed as normal.

He said workers were demanding a 70,000 rand (about $7,000) bonus fee because the project was nearing completion.

The construction of the stadium has been derailed by a number of strikes since work began about two years ago.

Last year, FIFA president Sepp Blatter announced that the more than 20,000 workers building South Africa's World Cup stadiums will get free match tickets.

FIFA has set aside cheaper tickets for the tournament, with 15 percent of the 3 million tickets expected to be sold priced at $20 — well below the top ticket price of $900. The low-priced tickets will be available only to those living in South Africa, a nation with high unemployment and poverty rates. The $20 is several times what South Africans pay for local soccer matches, but still affordable for many here.

Other prices range from $80 to $600. Tickets for the event, to be held June 11 - July 11 next year, will go on sale in several phases from Friday.

Organizers are optimistic about ticket sales but have expressed caution that the event may be affected by the global recession.

"I would be naive to suggest there will be no backlash as a result of the financial crisis that has spread round the globe," said David Will, chairman of the FIFA ticketing subcommittee, the South African Press Association reported Wednesday.

"But soccer fans are a funny breed who will go to South Africa come hell or high water if their own country qualifies for the World Cup," he said.

On the Web: http://www.fifa.com