DUBAI, Oct 18 (Reuters) - Qatari Investors Group , a firm primarily involved in production and distribution of cement, reported a 3.5 percent rise in third-quarter net profit on Tuesday, according to Reuters calculations.

* Net profit of 61.58 million riyals ($16.91 million) in the three months ending Sept. 30 versus 59.50 million riyals a year earlier.

* Reuters calculations are based on financial statements in lieu of a quarterly breakdown.

* Qatari Investors Group nine-month net profit 220.32 million riyals, up from 186 million riyals a year ago, a bourse statement said.($1 = 3.6412 Qatar riyals)

(Reporting by David French; Editing by Sunil Nair) ((davidj.french@thomsonreuters.com; +971 4 362 5864; Reuters Messaging: davidj.french.thomsonreuters.com@reuters.net))