China National Petroleum Corporation (CNPC) announced Wednesday that it had concluded an agreement with Shell under which CNPC has acquired a 35-percent stake in Syria Shell Petroleum Development (SSPD), a unit of Royal Dutch Shell.

SSPD has interests in three production licenses -- Deir-Ez-Zor, Fourth Annex and Ash Sham -- that are operated by the Al Furat Petroleum Company (AFPC), in which Shell has an interest of 31.25 percent, said a statement released by CNPC on its website.

Both CNPC and Shell in China declined to disclose the cost for the deal.

The agreement strengthens the partnership between Shell and CNPC. Both parties would look to continue growing and investing in opportunities in Syria's upstream industry, said the statement.

The licenses cover 40 oil fields, in which Shell had a share of 23,000 barrels oil equivalent per day last year.

Shell has had a presence in Syria since the 1940s and been a shareholder in AFPC for 25 years.

CNPC already has an interest in the three production licenses and in AFPC through its 50-percent ownership of Himalaya Energy Syria BV.

Himalaya Energy Syria Bv is a joint venture between CNPC and ONGC, the state-owned oil company of India.