Tenders for offshore oil and gas exploration and exploitation west and south of Greece have attracted “strong interest” from companies exploring in the Mediterranean, the head of Greece’s oil and gas resources management company said on Wednesday.

Greece launched the tenders after expressions of interest by a consortium of Exxon Mobil, Total and Hellenic Petroleum for two sites off the island of Crete and by Greece’s Energean for a block in the Ionian Sea.

Offers must be submitted to the Hellenic Hydrocarbons Resources Management (HHRM) company.

“HHRM is happy because the companies involved in exploration in the southeast Mediterranean have shown strong interest or have visited data rooms,” Chief Executive Yannis Bassias told Reuters. Bassias declined to name the companies because the tender process is ongoing, according to Reuters.

As well as Exxon and Total, Israel’s Delek, Italy’s Eni and U.S. Noble Energy are currently exploring off Israel or Egypt.

Delek Group and its subsidiary Delek Drilling declined to comment. Noble did not immediately respond to a request for comment. Eni has said it bought data packages to see if Crete was of interest.

Investors have until early March to submit offers and Bassias expects preferred bidders to be announced by May. The preferred bidder must be formally approved by the energy ministry and the concession ratified by parliament.