* Third worker dies helping to build Arena Corinthians
* Man fell installing temporary stands for the finals
* Brings fatalities to seven across Brazil's World Cup arenas
* FIFA official says "very saddened by the tragic death"
Another man has died while helping to build the Sao Paulo stadium that will host the opening match at this year's World Cup in Brazil, a hospital spokesperson said on Saturday.
He is the third construction worker to perish while working on the Arena Corinthians on the outskirts of Sao Paulo and the seventh to die in building Brazil's World Cup arenas.
Fabio Hamilton da Cruz fell about 25 feet to his death on Saturday morning, said a spokesperson for the Santa Marcelina hospital where he was taken.
He was installing floors on the temporary stands being constructed at the ground that will host the Brazil-Croatia opener on June 12, Corinthians said in a statement.
Brazil's Sports Minister confirmed Saturday's death and said he would wait for a full report about the incident.
"The Sports Ministry registers its deepest sympathies over the death of Fabio Hamilton da Cruz," it said in a statement. "We express our total solidarity with his family and friends."
FIFA secretary general Jerome Valcke tweeted that he was "very saddened by the tragic death" of the worker and sent his condolences to the man's family and friends.
Fatal accidents have also occurred in Manaus and Brasilia.
Another worker died while working on Palmeiras's arena in Sao Paulo, but that stadium will not be used for the World Cup.
Two workers lost their lives building stadiums for the World Cup tournament hosted in South Africa four years ago.
The Arena Corinthians is among the most expensive of Brazil's 12 World Cup venues and was one of the last to get started.
It is designed to seat 48,000 people but another 20,000 seats are being added for use during the finals.
The construction worker who died on Saturday was helping to install the temporary stands when he fell, a statement published on the Corinthians website said.
The stadium was supposed to be finished in December but the delivery date was pushed back after two workers were killed in November when a crane toppled over.
Work has been slow since then and there is concern that security may be taking a back seat to haste as workers rush to finish the venue in time.
The stadiums in Cuiaba and Curitiba are still not finished, although the latter held its first game on Saturday.
Only small sections of the Arena da Baixada were open for the game between the hosts Atletico Paranaense and J Malucelli which ended in a 0-0 draw.
The 2014 World Cup, the first to be held in Brazil since 1950, has been beset by delays, cost overruns and broken promises.
In addition to the late delivery of stadiums, several important public transportation projects have been scaled back or abandoned altogether.
There are also concerns that the temporary structures needed to help with issues such as energy, security and hospitality will not be ready in time.
Sao Paulo and Porto Alegre have yet to start deploying the tents and containers required and they have not begun to install the telecoms networks needed by broadcasters and the media.
Organisers said those networks have to be in place 90 days before the tournament begins in order to properly test them but with 75 days to go before the first ball is kicked work has not yet started.
FIFA last week said it remained confident everything will be finished in time for the start of the finals. The soccer world governing body's secretary general Valcke has been meeting with Corinthians officials to discuss the delays.