A Delaware federal judge has allowed Crystallex International Corp. to seize shares of Citgo Petroleum Corp., granting the Canadian gold producer’s request to prevent Venezuela from avoiding a $1.2 billion arbitration award over lost mineral rights.

The ruling, initially filed under seal Aug. 10 by U.S. District Chief Judge Leonard P. Stark of the District of Delaware, entered a writ of attachment for shares of Petróleos de Venezuela S.A., Venezuela’s national oil company, which owns Citgo in the United States—the latest development in a messy international dispute that has bounced around the federal courts for years.