Israeli conglomerate Delek Group is considering spinning off its holdings in the large Tamar natural gas field into a separate publicly traded company.

Under a deal reached with the Israeli government to boost competition in the sector, Delek has about five years to sell its 31.25% stake in the offshore field, which holds 11 trillion cubic feet of gas.

However, finding a single buyer could prove difficult. Delek's share in Tamar is worth close to $4 billion, based on the price achieved in the recent sale of a 3% stake by operator Noble Energy Inc. (NYSE: NBL).

Delek's CEO Asaf Bartfeld told analysts in a conference call late on Aug. 30 that the company might decide to set up a new entity that can be offered on capital markets.

Such a flotation would have to be done abroad, Bartfeld said, because the new company would be too big for the Tel Aviv Stock Exchange.

The public offering would not have to be for the entire stake in the Tamar Field, an industry source said; and Delek is also exploring the possibility of selling some of its holding to a third-party buyer and spinning off the rest.

A final decision is at least a few months away, the source said.

Delek owns its stake in Tamar through subsidiaries Delek Drilling and Avner Oil.