Kazakhstan and a group of oil majors led by Chevron approved on Tuesday a $36.8 billion plan to boost production at the Tengiz field, the Central Asian nations's Energy Ministry and foreign partners said in a joint statement.

The super-giant field, one of the world's biggest, accounts for more than a third of total crude output in Kazakhstan which is the biggest ex-Soviet oil producer after Russia.

Under the plan, Tengiz, in which Exxon Mobil and Lukoil also have stakes, will increase output to 39 million tonnes a year (850,000 barrels per day) by 2022 from 27 million tonnes currently.

"Today we are witnessing a historic event not just for the oil and gas sector but for the whole country," Kazakh Energy Minister Kanat Bozumbayev told reporters in Astana, sitting next to executives of Tengizchevroil, the joint venture operating Tengiz, and partner companies.

In a separate statement, Chevron said the total project budget included $27.1 billion for facilities, $3.5 billion for wells and $6.2 billion for contingency and escalation.

Kazakhstan holds a 20 percent stake in the venture via state oil and gas firm KazMunayGaz. Chevron owns 50 percent, Exxon Mobil has 25 percent and Lukarco, controlled by Russia's LUKOIL, the remaining 5 percent.