Richard Desmond's Channel 5 is poised to sign a £200m five-year deal to bring back Big Brother following months of tortuous negotiations between his company and the programme's producer, Endemol.

There were hopes that the deal could have been announced this week, but last-minute legal wrangles continue to delay the announcement of a plan that has been mooted since Desmond bought the channel last summer.

Because of the time taken by the talks, the earliest Big Brother could come back on air is understood to be August. A three-week run of Celebrity Big Brother is expected to be followed by a run of Big Brother into the autumn and winter.

Desmond is hoping he could lure Cheryl Cole into hosting Big Brother – an effort fuelled by this morning's Daily Star splash "Cheryl's New B Bro Babe" – but the star's camp totally dismissed the public overtures.

"Cheryl has not been approached, and she has no interest in presenting Big Brother," said a spokesman for the singer, noting that star was still waiting to hear whether she would be able to present The X Factor in the US.

So difficult have the Channel 5-Endemol discussions been that Desmond and Ynon Kreiz, the Endemol chief executive, are no longer speaking. That led to talks collapsing in the autumn, and the negotiations only resumed with the intervention of Michael Sherwood, the vice-chairman of Goldman Sachs, whose bank is a one-third shareholder in Endemol.

After the falling-out, Desmond – who still wants Big Brother for the ratings he thinks it will bring – delegated responsibility for the negotiations to Jeff Ford, the Channel 5 director of programmes.

Only in 2012, would Big Brother return to its traditional schedule – running the celebrity show in January, before reappearing with the traditional group of wannabes in the summer months.

That would mean an almost continuous run of Big Brother programmes – running night after night – on Channel 5 from August to January. At the same time, the channel plans to revamp its schedule, with programmes such as Candy Bar Girls, a reality show documenting the "life and loves" of six lesbians who work in a bar in London's Soho.

Channel 5 was expected to generate £260m in revenues in 2010 at the time of its sale by RTL to Desmond for £103.5m in July. But the uptick in the ad market has taken that figure to close to £300m and the channel is generating an estimated £3m of operating profit a month.

This year, Channel 5 is aiming to generate £350m in turnover, again helped by a strong start for TV advertising in 2011, but the anticipated spend on Big Brother and other new programmes may mean that profit growth is not as rapid as the turnover growth implies.

Desmond's company, Northern & Shell, declined to comment.