Brazilian state-run energy giant Petroleo Brasileiro (PBR, PETR4.BR) revised downward its investment plan for the 2011-2014 period, the company said late Monday in a statement.

Petrobras now expects to invest up to 250 billion Brazilian reals ($138.8 billion) in its operations through 2014, down from BRL265 billion announced earlier this month. The investment plan was approved by the company's board.

The company didn't unveil the reason for the downward revision.

For the post-2014 period, Petrobras said it approved a set of projects for a total investment of about BRL462 billion. Part of the investments represent the development of projects that already are included in the 2010-2014 portfolio but have maturity time longer than the five-year business plan.

The company, which based the figure on a preliminary view, said this is in line with its vision for 2020.

About 61.5% of Petrobras' 2011-2014 investment budget will be focused on exploration and production.

"In the Exploration and Production (E&P) area, the investments aim to increase oil and natural gas production, taking advantage of the success that was achieved in the post- and pre-salt and also the exploratory activities. The E&P project portfolio includes the construction of production platforms and drilling rigs, support vessels, and investments in infrastructure for transportation," Petrobras said.