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By Lamine Chikhi

ALGIERS, Oct 11 (Reuters) - Algeria's state energy company Sonatrach has awarded Japanese firm JGC Corp. a $1.4 billion contract to boost production at its largest gas field Hassi Rmel, an internal Sonatrach document seen by Reuters showed.

It was the second contract for JGC in 2016, the first one was awarded in March for $339 million and involved boosting output at Algeria's biggest oilfield Hassi Messaoud.

The Engineering Procurement and Construction (EPC) contract includes the installation of equipment to boost the Hassi Rmel gas field which produces half of Algeria's gas output.

Fourteen foreign firms participated in the bidding.

OPEC member Algeria has been hit hard by the slump in world oil prices and has struggled to attract energy investment to help develop new fields and increase existing production.

Algeria's government has said it is looking to develop existing fields such as Hassi Rmel, Hassi Messaoud, Berkine and El Merk to increase oil and gas production.

Algeria's gas output is estimated at 132.2 billion cubic metres. It is expected to reach 141.3 bcm in 2017, 143.9 bcm in 2018, 150 bcm in 2019 and 165 bcm in 2020, according to Sonatrach's CEO Amin Mazouzi.

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