The group has bid to supply Cyprus' state-run natural gas company, DEFA, between 0.7 to 0.95 billion cubic meters (bcm) of gas annually for up to 10 years, said Israeli conglomerate Delek Group, whose units Delek Drilling and Avner Oil hold key stakes in Leviathan.

The plan would be to build a pipeline from the field, which is located in the eastern Mediterranean between Israel and Cyprus, and supply DEFA with gas starting in 2016 or 2017, Delek said. The deal would last until 2022 or 2025.

Leviathan, discovered in 2010 by Delek, along with Texas-based Noble Energy and Ratio Oil, was the world's largest offshore find of the past decade. It holds an estimated 530 bcm of gas, much of which is earmarked for export.

Cyprus will make its decision by Aug. 21, Delek said in a statement.

Israeli financial daily Globes reported that other bids have come from Dutch-owned oil trader Vitol, a group led by Azeri state oil company SOCAR, and a Greek consortium.

A source close to the Leviathan partners said they have a good chance of beating out the other bidders because they are the only ones able to supply gas through a pipeline, rather than more expensive liquefied natural gas (LNG).

Delek and Noble have made a few other sizeable discoveries in the area, including one in Cypriot waters, and are exploring options on how best to develop them for export. One idea that has been discussed is to build a LNG facility on Cyprus' coast.

"If Leviathan is chosen to supply gas to DEFA, it would potentially improve relations with Cyprus in the field of natural gas. If a pipeline is already being built, it might open new options," the source said.

Source: Reuters