DUBAI, April 25 (Reuters) - Du, the United Arab Emirates' No.2 telecom operator, reported a 24 percent fall in first-quarter net profit on Tuesday, missing analysts' expectations.

The company has been squeezed since late 2014 as growth of the mobile market has been offset by a steady increase in the royalty - or tax - paid to the government.

Du, which ended rival Etisalat's domestic monopoly in 2007, made a net profit of 364.9 million dirhams ($99.35 million) in the three months to March 31, down from 480.1 million dirhams in the year-earlier period.

SICO Bahrain had projected a net profit of 447.33 million dirham and EFG Hermes had estimates of 474.02 million dirham for the telecoms operator.

First-quarter revenue was 3.17 billion dirhams. This compares with 3.09 billion dirhams a year ago.

Du paid quarterly royalties - or tax - of 486.3 million dirhams, down from 541.2 million dirhams in the prior-year period.

Chief Executive Osman Sultan said on Feb. 16 the telecommunications firm would target 1 billion dirhams ($272 million) in savings by 2019 as government taxes erode profit.

($1 = 3.6729 UAE dirham)

(Reporting by Alexander Cornwell and Saeed Azhar; Editing by Kim Coghill) ((alexander.cornwell@thomsonreuters.com))