Channel 5 will increase its original primetime programming under the terms of its £463m acquisition by Viacom.

Ofcom today formally rubber-stamped the US broadcasting giant’s purchase of the channel from Richard Desmond, five months after it was originally agreed in May.

Under the terms of the licence agreed with Ofcom, C5 will increase the minimum amount of original programmes it shows daily between 6.30pm and 10.30pm from 40% to 45%.

The channel has also agreed to increase its output of news programmes from 260 to 280 hours per year, and has extended ITN’s contract to produce its 5 News bulletins by two years to 2017.

The changes to the licence are due to run until 2025.

The deal with Viacom represents a handsome profit for Express Newspapers owner Desmond, who bought the channel from the RTL Group in 2010 in a deal worth £103.5m.