One of the presenters of Channel 4's troubled breakfast show Rise, Colin Murray, is leaving the early morning programme.

The show, which is a mixture of serious and irreverent news, has been hit by low ratings and press criticism since it launched nearly six months ago.

Now Murray, 25, one of the show's five lead presenters, is leaving to concentrate on late-night music programmes for Channel 4.

A spokeswoman for the show said: "We can confirm we have parted company with Colin."

Five's Bear In The Big Blue House has been beating Rise

A spokeswoman for Murray's agent said he was "excited" to be concentrating on the late-night 4 Music strand, and a new entertainment series called Born Sloppy.

He also presents BBC Radio 1's Session in Northern Ireland show, and he has been tipped as one of the prime candidates to front a possible replacement for the network's Evening Session show when it is ends later this year.

Beaten by Noddy

Unofficial overnight ratings showed Rise, which has struggled with ratings, picking up audience shares of between 3.9% and 5.9% last week - compared with GMTV's regular 30% share of the audience.

It is regularly beaten by Five's early morning offerings such as Noddy and Bear in the Big Blue House.

The show has also been hit by a number of high-level departures. Most recently its producer, Deborah Turness, left to take up the deputy editor's job at ITV news.

But until now its presenting team, led by former Sky rugby anchor Mark Durden-Smith, had remained intact.

Unusually, the show went for five lead presenters: Durden-Smith, former Newsround host Chris Rogers, Sky Sports presenter Kirsty Gallacher, MTV's Edith Bowman and Liz Bonnin, recruited from Ireland's RTE network.

Most of them work on the show for a couple of days each week, with Durden-Smith leading the team each morning.

Although there is industry speculation about the programme cutting its presenting team down, its spokeswoman said there were no changes planned for the format.

"We've a two-year contract with Channel 4, which is committed to the show's future," she added.