DOW JONES NEWSWIRES State-controlled oil producer OAO Gazprom Neft (SIBN.RS) has lost a legal fight against Russia's antitrust regulator, which fined it and other companies for price-fixing, business daily Vedomosti reports Thursday. The Constitutional Court on Wednesday refused to consider Gazprom Neft's challenge to the national law on competition, saying the company's argument was insufficient to warrant a review. Judges also questioned whether the person who signed the appeal on behalf of Chief Executive Alexander Dyukov had authority to do so. And they said the company filed with the high court too soon, before it had exhausted all appeals with the Federal Anti-Monopoly Service. The FAS in late 2008 fined Gazprom Neft 6 billion rubles for abusing its market power in the pricing of refined-oil products. Its case is still being considered by the Moscow Arbitration Court and a federal arbitration tribunal. Given Wednesday's decision but with litigation continuing, it's hard to predict the final result for the company. Gazprom Neft was rebuffed in its request to have the lower-court proceedings transferred to the Constitutional Court. A Gazprom Neft spokesman said Wednesday that he didn't know whether the company would amend and refile its complaint to the court. Three other producers fined by the FAS for price-fixing -- state-controlled OAO Rosneft (ROSN.RS), nonstate OAO Lukoil (LKOH.RS) and BP PLC (BP, BP.LN) joint venture TNK-BP (TNBP.RS) -- also waged court fights over the penalty amounts. Only Gazprom Neft, after losing an appeal in Russia's Supreme Arbitration Court, moved to challenge the FAS's constitutional authority to impose such fines. In late May, the Supreme Arbitration Court upheld the RUB1.1 billion fine against TNK-BP. Newspaper website: www.vedomosti.ru -Dow Jones Newswires; 212-416-2900 (END) Dow Jones Newswires July 21, 2010 23:39 ET (03:39 GMT)