UPDATE 1-Brazil to pump first Tupi oil in May

(Changes dateline, releads with new oil output in May)

By Fernando Exman and Peter Murphy

BRASILIA, March 6 (Reuters) - Brazil's state-controlled energy firm Petrobras (PETR4.SA: Quote, Profile, Research)(PBR.N: Quote, Profile, Research) will extract its first crude oil on May 1 from the potentially huge find it made below the salt layer of the Santos basin in late 2007, the country's president said on Friday.

The oil will be drawn from offshore subsalt reserves found in the 5-to-8-billion-barrel Tupi oil field, one of the largest deep water finds in history. It is part of a broader structure of oil at a depth of up to 7 kms (4.4 miles) that analysts have said could contain 50-80 billion barrels.

"What will happen is very important. We're going to extract the first barrels of oil at a depth of 6,000 meters. That is no small feat," President Luiz Inacio Lula da Silva said, inaugurating a gas treatment plant in Espirito Santo state.

Initial subsalt output from the Tupi field will be around 15,000 barrels per day rising to 30,000 barrels a day during a later stage of testing and then to around 100,000 barrels per day by 2010 when it will be in a more advanced pilot phase.

The Tupi oil will not be the first subsalt crude to see the light of day. Crude was pumped to great fanfare last September from a much smaller field in Espirito Santo state.

Petrobras said on Friday that it posted its largest-ever one-day output of Brazilian crude oil this week after several new platforms recently came on line.

The firm produced 2,012,654 barrels on Wednesday which was 12,420 barrels more than the previous record set on Christmas day of 2007.