The deals were signed with Dorad Energy Ltd and two subsidiaries of the Edeltech Group, Ashdod Energy and Ramat Negev Energy.
Energean's deal with Dorad is for the supply of up to 6.75 billion cubic metres (BCM) of gas over at least 14 years, while Ashdod and Ramat Negev will get up to 2.65 billion cubic metres together. Financial details for the deals were not included.
The Karish and Tanin fields, located off the coast of Israel, are expected to go online in 2020.
Energean has signed deals for a total of up to 33 BCM in volume, securing revenue of approximately $3 billion.
(Reporting by Dan Pleck)