Six international companies have apparently submitted bids to develop Qatar’s largest offshore oil field, including heavy hitters BP and Royal Dutch Shell, Reuters reports. It added that the others are Maersk , Total SA, Chevron Corp. and ConocoPhillips, according to sources close to the matter.

Maersk has been operating the Al Shaheen field since 1992, but its agreement with Qatar Petroleum (QP) expires next year. Earlier this month, the Danish energy firm conceded that its time on the project may be coming to an end after QP launched a new tender process. Reuters said this was because Qatar wants to increase production at the field.