Rio de Janeiro - Brazilian oil giant Petrobras announced an $11 billion bond issue Tuesday, a record for an emerging country company.

The state-controlled company, which already carries a huge debt load, is raising funds for its $237 billion five year investment program, including the development of deep water oil fields off the coast of Brazil.

This year alone, Petrobras plans to take on $20 billion in debt, its financial director said recently.

The US dollar bonds are being issued with maturity periods of three, five, ten and 30 years at both fixed and variable rates.

The fixed rates range from 2.14 percent for a three year bond to 5.76 percent for a thirty year bond.

Market sources cited by Dow Jones Newswire say demand has been strong at over $40 billion, or nearly four times the amount sought.

Petrobras wanted to sell off assets to finance its projects, but a lack of buyers has forced it to take on debt.

It comes ahead of auctions Tuesday and Wednesday of concessions by the state to develop 289 oil blocks in the unexplored north and northeast of the country.

The offering - with untapped reserves estimated at 9.1 billion barrels - has attracted dozens of companies, including Petrobras, that hope to repeat the big oil discoveries made in 2008 along the southeastern coast. - Sapa-AFP