A Siberian court Wednesday refused to grant a minority shareholder of BP's PLC (BP.LN) Russian joint venture OAO TNK-BP Holding (TNBP.RS) more time to bolster shareholder support for his $2.8 billion lawsuit against two BP executives on the board of TNK-BP.

The court of arbitration in the West Siberian city of Tyumen told the plaintiff, Andrey Prokhorov, who owns a 0.0000106% stake in TNK-BP, he couldn't proceed with bringing more of the company's shareholders on board for the complaint.

The court will now hear Prokhorov's complaint on Nov. 10.

BP faces another lawsuit, claiming damages of $4.9 billion, filed by Prokhorov and other minority shareholders.

In both cases the plaintiffs claim BP unlawfully blocked TNK-BP's efforts to promote itself rather than BP as a partner of state-controlled oil company OAO Rosneft (ROSN.RS) in an Arctic exploration alliance that collapsed in May.

BP has said the allegations are "baseless and legally insupportable," arguing that no losses were incurred by TNK-BP and that the BP's board members at TNK-BP acted in the best interest of the company.