Argentina's state energy company YPF SA (NYSE: YPF) said on March 16 it appealed a local court ruling ordering it to disclose details of its contract with Chevron Corp. (NYSE: CVX), amid allegations of secret clauses in the agreement.

Chevron in 2013 signed a deal to explore the Vaca Muerta shale formation. It was the largest foreign investment in Argentine energy since the government seized Spanish giant Repsol SA's controlling stake in YPF the year before.

Opposition lawmakers believe the contract contains secret clauses that hand concessions to Chevron and undermine national interests.

"Shareholders decided to appeal the resolution issued by the Administrative Court Federal No. 7," YPF said in a statement.

On March 16 the court gave YPF five days to disclose contract details. The Supreme Court said in November that the company "cannot deny access to information of unquestionable public interest."