HASSI MESSAOUD, Algeria, Feb 24 (Reuters) - Algeria's biggest oilfield Hassi Messaoud is currently capping production at 430,000 barrels per day to keep it in line with OPEC's agreement to cut output, a Sonatrach official said late on Thursday.

Algeria, a major gas supplier to Europe, last year began investing in improving yields at mature fields like Hassi Messaoud and bringing delayed gas fields online in the south, aiming to reverse stagnant energy production.

"We could have done more, we could produce more oil, but we must respect our quota," Hassi Messaoud's production chief Ali Neghmouche told Reuters at the field.

The North African OPEC member was hit hard by the crash in global oil prices, which hammered its energy revenues. It has been working to increase output, and trim its budget. Oil and gas earnings make up 60 percent of state spending.

Algeria's total oil output was previously estimated at 1.1 million bpd, but it has cut production by 50,000 barrels to adhere to an agreement by OPEC members to trim output. That deal should end in June if it is not extended to the end of this year.

Neghmouche said Algeria was taking the OPEC quota deal as an opportunity to also do some maintenance on Hassi Messaoud facilities.

"We have 1,500 wells and we continue to dig in the Hassi Messaoud region," he said.

(Reporting by Lamine Chikhi; Editing by Patrick Markey and Susan Fenton) ((pat.markey@thomsonreuters.com; +213-661-692993; Reuters Messaging: pat.markey.thomsonreuters.com@reuters.net))