May 8 (Bloomberg) -- Goldman Sachs Group Inc. boosted its U.S. share-price forecast for Petroleo Brasileiro SA by 25 percent as the Brazilian oil producer’s development of the pre- salt region may give support to valuations.

Investors should take a “longer-term view of Petrobras,” as the Rio de Janeiro-based oil company is known, because the offshore reserves won’t contribute cash flow until “some time next decade,” analyst Arjun Murti wrote in a note.

Petrobras, rated “buy,” is the analyst’s “favorite” among oil companies, according to the note. Murti expects the American depositary receipts to trade at $50 each in six months, compared with the previous share-price estimate of $40.

To contact the reporter on this story: Paulo Winterstein in Sao Paulo at pwinterstein@bloomberg.net.

Last Updated: May 8, 2009 09:22 EDT