Reports on "LG Caltex Gas Co Ltd and Conitgroup Companies Inc v China National Petroleum Co and China Petroleum Technology and Development Corporation" where it was ruled that the existence of an ad hoc agreement regarding the arbitrator's jurisdiction can be challenged under the Arbitration Act 1996 s67; that if such an agreement isfound to be valid then neither party can challenge the arbitrator's right to make the award and s67 ceases to be material; and that by appearing in the arbitration and not raising any objection a party may lose its right to challenge the validity of the ad hoc agreement except where there is an express reservation of rights. It was also held that where the validity is successfully challenged the court is entitled, by means of an application under s67, to examine if the arbitrator had considered the jurisdictional issues correctly in making the award, providing that the applicant had not lost his right to object. If the challenge is unsuccessful then the only the merits of the award can be challenged under s68.