A reduction in tariffs prevented revenue growth at Jersey Electricity, the sole supplier of electricity to the island of Jersey, in the six months to 31 March.Pre-tax profits fell to £6.9 from £7.5m over the same period the previous year on revenues that were steady at £55.7m.Electricity revenues in the first half of 2011 were 1% lower than in 2010 at £42.2m, the company said. Unit sales volumes were up 2% but this was offset by the year-on-year impact of the 5% decrease in customer tariffs from January 2010.Jersey Electricity is paying a 4.25p dividend, up from 4.05p restated the previous year."Your board aims to deliver sustained real growth each year and the proposed interim dividend is a 5% year on year increase," the company said.