Falling output at the main Azeri, Chirag and Guneshli (ACG) oilfields has been a cause of concern in Baku.

British oil major BP and its partner, Azeri state energy firm SOCAR, tried to calm those worries last year, saying production had stabilised. Total oil output rose last year for the first time since 2011.

But the decline continued this year. Output from the ACG fields fell to 24.2 million tonnes, or an average 655,700 barrels per day (bpd) in January-September from 663,200 bpd in the same period last year and 656,000 bpd in the first half of 2014, BP-Azerbaijan said in November.

BP started maintenance work at the Central Azeri and West Azeri platforms on Oct. 31, halting operations for a month, in a move that could further reduce oil production in the country. Production resumed on Nov. 27.

Oil production falls at fields operated by BP led to 3.6 percent year-on-year decline in Azerbaijan's oil exports in the first 11 months of 2014, a source at the State Customs Committee said on Monday.

The source said Azerbaijan exported 30.2 million tonnes of oil, down from 31.4 million tonnes in the same months of 2013. Exports of oil via Russia through the Baku-Novorossiisk pipeline amounted to 933,336 tonnes in the 11 months, down from 1.58 million tonnes.

Exports through the Baku-Supsa pipeline via Georgia rose to 3.855 million tonnes from 3.652 million tonnes, while exports through Baku-Tbilisi-Ceyhan via Georgia and Turkey were 24.6 million tonnes, down from 25.2 million tonnes.

Oil exports shipped by rail via Georgia declined to 855.575 tonnes from 896.525.

Azerbaijan plans to produce 41.2 million tonnes of oil in 2014, down from 43.5 million tonnes in 2013, and 28.8 bcm of natural gas, down from 29.5 bcm produced last year.