BG Group, the UK gas exploration and production firm, has expanded its interest in Egypt, buying Shell's stake in a joint venture project.
The deal, which is subject to Egyptian government approval, doubles to 80% BG's interest in the Rosetta concession off the Nile Delta.
It pre-empts Shell's planned sale of the stake to a Kuwaiti company.
The other partner in the project - which supplies Egypt's domestic market - is Italy's Edison with a 20% stake.
"This pre-emption provides us with an excellent opportunity to increase our position in a high-quality, BG Group-operated asset," said Stuart Fysh, BG's executive vice president and managing director for the Mediterranean Basin and Africa.
The Rosetta concession was awarded in 1997 and started production in 2001.
BG also has a 50:50 joint venture with Malaysia's Petronas to produce gas from the West Delta Deep Marine concession off Egypt's north coast.
Its Scarab Saffron fields, which went into production in 2003, are Egypt's largest developed gas fields and also supply the domestic market.
Egypt's proved reserves of natural gas are modest by regional standards. At the end of 2003, they stood at 62 trillion cubic feet (1.76 trillion cubic metres), according to BP's statistical review of world energy.
This compared with Algeria's 160 trillion cubic feet and regional gas giants Iran and Qatar, which each have proved reserves of more than 900 trillion cubic feet.