DUBAI, Jan 31 (Reuters) - Vodafone Qatar, an affiliate of Vodafone Group, reported a narrowing third-quarter loss on Tuesday, according to Reuters calculations.

The operator made a net loss of 31.5 million riyals ($8.7 million) in the three months to Dec. 31, according to Reuters calculations.

That compares with a loss of 72.2 million riyals in the prior-year period.

Vodafone Qatar, which uses a financial year starting on April 1, has yet to make a quarterly net profit since ending state-controlled Ooredoo's domestic monopoly in 2009 as the latter has fought hard to bolster its revenue share.

The firm, which halted a run of disappointing earnings performances by reporting a narrowing second-quarter loss, reduced headcount by 10 percent in May, with some job cuts permanent and other positions to be reassigned to roles aimed at boosting mobile revenue streams, it confirmed in July.

Vodafone Qatar's net loss in the nine months to Dec. 31 was 195 million riyals, it said in a bourse statement, compared to a 286 million riyals loss in the same year-ago period.

($1 = 3.6412 Qatar riyals)

(Reporting by Alexander Cornwell; Editing by Tom Arnold) ((Alexander.Cornwell@thomsonreuters.com;))