British energy producer BG Group said yesterday that an oil and gas field it helped to discover off the coast of Brazil holds between 1.1 and two billion barrels.

"The Guara discovery in the Santos Basin pre-salt, offshore Brazil is now estimated to contain recoverable volumes of 1.1 to two billion barrels of oil equivalent," BG said in a statement.

The British group owns 30 per cent of the field whose discovery was announced in 2008 and which is operated by Petrobas owing to the Brazilian company's 45 per cent stake. Repsol of Spain owns the remaining 25 per cent.

BG Group said Guara was capable of initially producing up to 50,000 barrels of oil or gas per day from 2012, potentially rising to 120,000 barrels.

"The well test results on Guara were excellent and underscore again the outstanding potential in BG Group's extensive position in the world-class Santos Basin," BG Group chief executive Frank Chapman said in the statement.

"It is clear that the Santos Basin pre-salt will make a very material contribution to the production and cash flow of BG Group for many years to come," he added.

The announcement comes one week after British energy major BP said it had made a major oil discovery in the Gulf of Mexico after drilling one of the industry's deepest-ever wells. Repsol president Antoni Brufau said the estimate that the field could hold up to two billion barrels of oil "surprised us all in a positive way".