DUBAI, Jan 18 (Reuters) - Telecom Zain Saudi 7030.SE reported a narrower fourth-quarter loss on Wednesday, beating estimates as revenue increased.

The company has yet to make a quarterly profit since launching services in 2008 and has battled to compete against better-resourced rivals Saudi Telecom Co 7010.SE (STC) and Etihad Etisalat 7020.SE (Mobily).

Zain Saudi, 37-percent owned by Kuwait's Zain ZAIN.KW , made a net loss of 135 million riyals ($36.00 million) in the three months to Dec. 31, according to a bourse statement. This compares with a net loss of 291 million riyals in the prior-year period.

Four analysts polled by Reuters had on average forecast Zain Saudi would make a quarterly net loss of 145.9 million riyals.

Quarterly revenue of 1.8 billion riyals was up from the 1.7 billion riyals recorded in the same period a year ago.

Zain Saudi's overall subscriber base fell 12 percent year on year to 10.9 million subscribers as of Dec. 31, 2016, the statement said.

Zain Group Chief Executive Scott Gegenheimer told Reuters on Nov. 10 Zain Saudi is likely to sell its mobile transmitter towers for over $500 million in the first half of 2017.

($1 = 3.7505 riyals)

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