Royal Dutch Shell Plc has sold 40% of its participation in two offshore oil exploration contracts in Colombia to Noble Energy Inc., which will also operate the blocks, the government said March 26.

Colombia recently modified contractual terms for offshore exploration and launched a permanent bidding process in an effort to boost its long-stagnant oil sector.

Neither the companies nor the national hydrocarbons agency (ANH) shared financial details of the deal for Noble's involvement in the Caribbean COL-3 and GUA OFF-3 blocks, which cover more than ​​880,000 hectares.

The ANH has previously said investment in the first development phase for the two blocks will hover around $100 million. Shell signed the contract for them earlier this month.

"This is a serious bet by two great companies on the potential of Colombian offshore," ANH President Luis Miguel Morelli said in a statement.

Colombia has some 1.78 billion barrels of reserves, equivalent to about 5.7 years of consumption, but wants to increase that to cover at least 10 years.

The Andean country produces about 860,000 barrels per day of crude, half of which is for export.