State-controlled oil giant Petrobras plans to invest $3.4 billion to expand production in the heart of Brazil's Amazon jungle.

The announcement coincides with the 25th anniversary of the start of operations in the Urucu petroleum province.

The money will go toward boosting extraction of oil and natural gas and on improvements to infrastructure at the Urucu complex, Petrobras executives told reporters here.

Urucu, an expanse of 342 sq. kilometers (132 sq. miles), currently produces 53,000 barrels per day of crude, nearly 11,400 cubic meters of natural gas and 1,300 tons of cooking gas.

Petrobras plans to increase production by building a 140-kilometer (87-mile) pipeline to transport gas from the Aracanga field to the Urucu complex, according to the company's chief of operations in Amazonia, Luiz Ferradans.

The construction two years ago of a gas pipeline from Urucu to Manaus, capital of Amazonas state, has cut the city's emissions of greenhouse gases by 1.2 million tons annually, Petrobras says.