Qatar Petroleum signed an agreement Wednesday allowing PetroChina Co. (PTR) to acquire from GDF Suez SA (GSZ.FR) a 40% stake in the country's exploration and production Block 4 field.

French utility GDF Suez will hold a 60% stake and will continue to operate the 2500 square-kilometer offshore block north of
Qatar , state-run Qatar Petroleum said in a statement.

The partners will start drilling in the next few months. PetroChina, a subsidiary of China National Petroleum Corp., or CNPC, China's largest energy producer, already has a 25% share in Qatar's Block D.

"Qatar is keen to have a broader bilateral cooperation with China and we see this as another step to further strengthen the friendly relations between the two countries," Qatari Oil Minister Mohammed Bin Saleh Al Sada said in the statement.

France 's GDF Suez is the third largest liquefied natural gas, or LNG, importer in the world, while Qatar is the largest exporter of the super-cooled fuel.