The Baku-Tbilisi-Ceyhan pipeline led by BP Plc (BP/) delivered 8 percent less Azeri oil in the first five months of the year, State Oil Co. (ATPG) of Azerbaijan said.

The line shipped 13 million metric tons, down from 14.2 million tons a year earlier, the company known as Socar said on its website without giving a reason for the decline.

The BTC pipeline, connecting the Sangachal terminal south of the Azeri capital of Baku to Turkey’s Mediterranean port of Ceyhan via Georgia, exports oil from the offshore Azeri-Chirag- Guneshli field, also operated by BP. As of June 1, BTC shipped 188.8 million tons of crude since it opened in 2006, Socar said.

The field produced 8.8 million tons of oil in the first quarter, down 8.3 percent from a year ago, BP said last month. Azerbaijan, the third-largest oil producer in the former Soviet Union after Russia and Kazakhstan, pumped 45.6 million tons of oil and 25.8 billion cubic meters of natural-gas last year.

To contact the reporter on this story: Zulfugar Agayev in Baku at zagayev@bloomberg.net

To contact the editor responsible for this story: Hellmuth Tromm at htromm@bloomberg.net