DUBAI, Aug 2 (Reuters) - Qatar's Gulf International Services reported a 67.2 percent fall in second-quarter net profit on Tuesday, according to Reuters calculations.

The firm, with interests in insurance, aviation, oil and gas and catering, made a net profit of 81.8 million riyals ($22.5 million) in the three months to June 30, Reuters calculated based on financial statements in lieu of a quarterly breakdown.

This was down from a net profit of 249.7 million riyals in the corresponding period of 2015.

QNB Financial Services had forecast Gulf International Services would make a quarterly profit of 108.1 million riyals.

Gulf International Services made a net profit of 160.7 million riyals in the first six months of 2016, according to a bourse filing, compared with 605.4 million riyals in the corresponding period of 2015.

($1 = 3.6415 Qatar riyals)

(Reporting by Tom Arnold; Editing by Mark Potter) ((Tom.Arnold@thomsonreuters.com; +97144536265; Reuters Messaging: tom.arnold.thomsonreuters.com@reuters.net))