DUBAI, Feb 4 (Reuters) - Dubai Financial Market DFM.DU (DFM), the Gulf's only listed stock exchange, reported an 89 percent drop in fourth-quarter net profit on Thursday as trading activity plunged, tracking a slump in oil prices.

The firm made a net profit of 15.5 million dirhams ($4.22 million) in the three months to Dec. 31, down from a net profit of 138.2 million dirhams in the year-ago period, Reuters calculated based on the DFM's annual financial statement.

HSBC forecast DFM would make a quarterly net profit of 20 million dirhams.

DFM's 2015 annual profit was 261 million dirhams versus 759.3 million dirhams in 2014, a statement from the firm said.

Trading commissions are the main source of income for DFM. The bourse traded 151.4 billion dirhams of shares in 2015, down 60 percent on 2014, according to the statement.

The company's board has proposed a 5 percent cash dividend for 2015.

Dubai's government owns a majority stake in DFM through holding company Borse Dubai.

($1 = 3.6726 UAE dirhams)

(Reporting by Matt Smith and Nadia Saleem; Editing by David French) ((matt.smith1@thomsonreuters.com; 00971506354039; Reuters Messaging: matt.smith1.thomsonreuters.com@reuters.net))