Du, the United Arab Emirates' No.2 telecom operator, reported a 0.6 percent fall in first-quarter profit on Tuesday, missing analysts' estimates as its mobile subscriber base shrunk slightly and it paid a higher tax rate than a year earlier. The company, which ended Etisalat's domestic monopoly in 2007, made a net profit of 487.1 million dirhams ($132.6 million) in the three months to March 31, down from 490.3 million dirhams from the prior-year period. Analysts polled by Reuters on average forecast du would make a quarterly profit of 564.7 million dirhams.