Gulf Keystone Petroleum's shares will be suspended on September 10th while investors wait for an English court to pass judgment on a legal claim concerning its Iraqi oil fields.The English Commercial Court will decide on claims brought by Excalibur Ventures against Gulf Keystone at 10:30 on September 10th. The judge will read his decision in open court.Trading in Gulf Keystone shares on AIM will be suspended from 07:30 until the company publishes a Stock Exchange announcement with details of the decision, probably later that day.The ruling will decide on a long-running dispute, worth up to $1.6bn (£1bn), between Gulf Keystone and Excalibur, ex-US Green Beret Rex Wempen's company. Wempen claims Gulf Keystone agreed in 2006 to give him 30% of any oil concessions it won in Iraq's Kurdistan region. Gulf Keystone has argued that Wempen did not meet his obligation under the agreement to contribute to exploration costs.