The figure, announced by Prime Minister Benjamin Netanyahu on Wednesday, is lower than the 53% recommended by an inter-ministerial committee last year. The remainder should provide Israel with enough gas for 25 years.
The decision ends months of uncertainty on export amounts. The cabinet is expected to approve the measure on Sunday.
The decision generated mixed reactions. The opposition and social organization which led the struggle against gas exports are persisting in their demand that the conclusion of the Zemach Committee, which looked into the government’s policy in terms of the natural gas market, be shelved and that the decision on the matter be handed over to the Knesset.
Opposition Chairwoman Shelly Yachimovich announced that she would petition the High Court of Justice against it along with Knesset Members Reuven Rivlin (Likud), Moshe Gafni (United Torah Judaism) and Economic Affairs Committee Chairman Avishay Braverman (Labor).
According to Yachimovich, the prime minister and ministers made the decision "without having any accurate information about the real needs of the economy in the future and the existing gas reserves, apart from the sloppy conclusions of the Zemach Committee."
She said the decision to allow drilling companies to export 40% of the gas was giving into the interests of the companies, which pay royalties according to the lower tariff of gas sales in Israel and will therefore earn more the more they export.
Israel began pumping gas from a large field off its coast earlier this year. A second, larger field destined for export is to go on line in 2016.
Netanyahu said Israel seeks to earn $60 billion over the next two decades from the exports.