Exxon held talks with TPAO in 2012 to discuss a partnership in shale, but the negotiations were inconclusive. According to Reuters, talks have since advanced and are now likely to result in an agreement.
Exxon is reportedly interested in onshore opportunities in the southeast, and in the Thrace Basin in northwestern Turkey.
Investors from the US, Europe, and Canada are also interested in Turkey's shale gas and oil, and Turkish officials may hold talks with potential investors in October.
Estimates of Turkey's shale gas reserves vary wildly. One energy official said data from some international bodies suggested Turkey could have a massive 20 trillion cubic meters (cbm) of total reserves. Another industry expert said proven reserves so far stood at just 6-7 billion cbm.