The two fields, discovered in 2011 and 2013, have combined 2C resources of about 2.4 tcf.
Energean will work on finalizing the transaction, and within six months from that date will submit to the Israeli authorities a development plan for both fields with a view to starting production in 2020.
It estimates the combined development cost at around $1 billion over the next few years.
CEO Mathios Rigas said: “The acquisition of Karish and Tanin and their development is a significant step for Energean, but it is also a big milestone forIsrael in developing its gas strategy, by bringing competition in the local market…
“Karish and Tanin will supply the Israeli domestic market for many years and we are eager to press ahead with its development as soon as possible.
“We will be …selecting our proposed contracting partners in the near future. We will also be starting negotiations with potential gas users and are confident that we can deliver competitive gas prices and services for Israeli consumers.”