Sky added 189,000 customers to its HD user base during the last quarter, taking the total number of Sky HD viewers to 3.7 million.

The total amount of HD customers is 47% higher than last year, but the rate at which the broadcaster is adding HD users appears to be slowing, with more than twice as many – 428,000 – added during the same period last year.

The three month period to the end of March was the first time in the last two years that the number of quarterly HD additions has dropped below 200,000.

In a statement, Sky said “demand for HD continues to be strong”.

It said: “As expected, net additions of 189,000 were lower than the prior year, in which we experienced exceptionally high demand in response to the launch of our free HD box.”

The pay TV operator added 51,000 new subscribers in its third quarter, with profits up by 24%.