Israel’s High Court of Justice struck down a deal that Prime Minister Benjamin Netanyahu reached in December to enable the development of a major offshore natural gas field, Leviathan, The New York Times reported.

The court specifically objected to a part of the agreement between the government and the project’s developers, which are led by Noble Energy, that prohibits changes to regulations affecting the project for 10 years.

The development of the Leviathan gas field that was to transform Israel into an exporter of the fuel has been plagued by delays. A supreme court ruling has left Israel’s government searching for ways to proceed. The decision was a blow to Netanyahu, who had appeared before the court to push forward the agreement reached with companies led by Noble Energy of Texas and Delek Group of Israel, wrote The Financial Times.

The court gave the government a year to work out an alternative solution, but that may lead to further delays in developing the field, which was discovered in 2010.

In light of the ruling, Israeli gas shares declined even after partners in Israel’s largest offshore gas field said a court ruling that blocked a proposal to regulate the natural gas industry will not derail their development plans, according to Bloomberg.