The club are eager to bring to an end any remaining suspicions that the 23-year-old is heading to Real Madrid this summer, and hope £10.4 million a year will be enough to do so.
According to the News of the World
, the new deal involves a weekly salary of £160,000 plus £40,000 for image rights and commercial activities.
Ronaldo's current contract - which pays him £120,000-a-week - has three years still to run, but according to Fifa rules he would be eligible to buy himself out at the end of the 2009/10 campaign.
With speculation over his future rife since the transfer saga of last summer, recent reports in Spain have suggested that Real and Ronaldo have a verbal agreement for a summer move, but this is vehemently denied by Sir Alex Ferguson.
"There is no question of Ronaldo leaving,' he said when asked of the rumours.
The paper also quotes a Portuguese source, who said: 'Cristiano wants to clear his head of the Real Madrid move once and for all. When he agreed to stay at United last summer he thought it would be just for one more year.
'But now he seems to be setting his mind on the long term because he realises he can fulfil all his ambitions at Old Trafford.'
Should the deal go ahead it would dwarf any other players salary in the league.
Premier League top earners [weekly]: Robinho: £160,000 John Terry: £135,000 Steven Gerrard: £120,000 Wayne Rooney: £115,000