To add details and background

Baku, June 1 (Reuters) - Kazakhstan's Energy Minister Yerlan Akinzhinov said on Monday that the country had restored its oil production to 290,000 tons per day after a previous production loss at the Tengiz field, the country's largest.

Kazakhstan produces two percent of the world's daily crude oil supply. This production is primarily exported via the Caspian Sea Pipeline Union to the Russian port of Novorossiysk.

Regarding barrels, Reuters calculations using a barrel-to-ton ratio of 7.5 indicate that Kazakhstan's production of crude oil and condensate is around 2.175 million barrels per day.

Two industry sources told Reuters on Friday that oil production at the Chevron-led Tengiz field fell sharply on May 26 as a result of an incident.

Chevron said in a statement on Friday that part of the Tengiz field experienced a "minor operational disruption" on May 28, and that production was being restored. No further details were provided.

Tengiz Chevroil, a Chevron joint venture, said on Monday that its oil production was "close to normal operating rates" after a brief disruption at one of its facilities on May 28.

An industry source said that oil production at Tengiz recovered to around 900,000 barrels per day on May 31, up from 310,000 barrels per day on May 28. The source added that Kazakhstan's average total oil and gas condensate production was 2.1 million barrels per day in May, down from 2.16 million barrels per day in April.

Production at the Tengiz field, located near the Caspian Sea in far western Kazakhstan, did not fully resume until April, after production was halted in January following a problem with electricity distribution.