Israeli and Turkish energy firms signed an agreement on Sunday to sell $1.3 billion worth of gas to Edeltech, Israel's Leviathan natural gas field offshore partners announced.

The Leviathan natural gas field was discovered in 2010 and holds an estimated 622 billion cubic metres (bcm) natural gas reserves, according to Xinhua.

The partners said they commit to providing 6 bcm within 18 years.

Edeltech and Zorlu Enerji, a Turkish energy conglomerate, will employ the gas to operate two new energy plants being established in southern Israel.

Both plants will provide energy to the industrial sector.

The privately owned Edeltech and Zorlu have already become partners with three energy plants in southern Israel.

The deal involves selling the first gas from the Leviathan reservoir to the Israeli market.

The agreement ensues two memorandums of understandings signed by the partners with neighboring Jordan and Egypt last year.

The Leviathan gas field and the smaller Tamar field are controlled by a consortium headed by Texas-based Noble Energy and Israel-based Delek Group.

Gas production in Tamar, however, kicked off in March 2013.

Noble believes that gas from Leviathan could be sold as soon as 2019, despite plummetting gas prices.

The long-awaited agreement allowing Noble and Delek to develop the Leviathan was finally signed in December 2015 by Israeli Prime Minister Benjamin Netanyahu.

Approval followed years of political upheaval and widespread public protest, with weekly rallies in major cities protesting against "selling out" the country's natural resources to a monopoly.