* Says Q3 net profit 29.4 mln rials vs 30.0 mln rials a year ago

* Q3 revenue 126.7 mln rials vs 119.0 mln rials a year ago

DUBAI, Nov 15 (Reuters) - Oman Telecommunications (Omantel) reported a 1.8 percent fall in third-quarter profit on Sunday as rising expenses and depreciation costs outweighed higher revenue.

The former monopoly made a net profit of 29.4 million rials ($76.37 million) in the three months to Sept. 30, it said in a stock exchange filing.

This compared with a profit of 30.0 million rials in the year-earlier period. Omantel has now reported falling profits in three of the past four quarters.

Two analysts polled by Reuters forecast Omantel would make a third-quarter profit between 26.6 million rials and 28.2 million rials.

Third-quarter revenue was 126.7 million rials, Omantel said in a statement. This compares with 119.0 million rials a year ago.

Staff costs, operating and maintenance expenses and depreciation of property, plant and equipment totaled 58.1 million rials in the third quarter, up from 52 million rials in the prior-year period according to Reuters calculations.

Shares in Omantel, which competes with Ooredoo Oman, ended 0.3 percent lower, slightly underperforming Muscat's index which fell 0.2 percent.

($1 = 0.3850 Omani rials)

(Reporting by Matt Smith; Editing by Keith Weir) ((matt.smith1@thomsonreuters.com; 00971506354039; Reuters Messaging: matt.smith1.thomsonreuters.com@reuters.net))