Sir Alex Ferguson has been given the go-ahead by the Glazer family to pursue another superstar but it is looking increasingly unlikely that he will be able to prise Ribery from Bayern Munich.
United are also keen on Wigan's Ecuador winger Antonio Valencia, and last night appeared close to clinching a deal.
Valencia has long been earmarked as a right-sided replacement for Ronaldo, who is on the verge of being sold to Real Madrid.
Headache: Ferguson has been told to replace Ronaldo with a player of equal stature
Last night, Wigan chairman Dave Whelan said: 'United will be in touch very shortly, I would imagine. They have actually put a cash offer on the table.'
Despite the cash from the Ronaldo deal, which United are insisting is paid up front, they are not willing to pay ridiculous money and that leaves Barcelona and Chelsea favourites to sign Ribery, valued by Bayern at around £65m.
Another hitch for United is that Ribery does not want to move his family to a north European climate.
Ferguson will continue to monitor the situation but is focusing his efforts on Valencia and trying to retain Carlos Tevez, still not sure of his intentions in light of an attractive offer from Manchester City.
Focused: Ferguson has earmarked Tevez and Valencia as top targets
As revealed by Sportsmail yesterday Ferguson drove the Ronaldo deal through once he became aware the Spaniards were willing to honour an agreement to pay £80m.
However, though the board or the Glazers would never tell Ferguson who to buy, it is also understood United are keen that their manager bring them a player of international repute in order to minimise the loss of selling one of their most commercially important players.
A big name that could one day reach the iconic status enjoyed by Ronaldo and, before him, David Beckham, is seen as ideal and Ribery and indeed Lyon's young forward Karim Benzema fit that bill.
Fitting the bill: Benzema and Ribery
Wayne Rooney, Rio Ferdinand and Dimitar Berbatov are valuable commercial tools, as well as key players, but have never quite managed to match Ronaldo's star billing across the world.
Young stars such as Italian teenager Federico Macheda, meanwhile, have the potential but their impact on United's profile depends on the rate of progress on the field.
Ferguson will be delighted that Wigan seem so happy to negotiate with United over Valencia, a player he was tempted to buy last summer.
Wigan owner Whelan added: 'I think they were waiting to see if Ronaldo actually went to Real. Things will develop now over the next seven to 14 days. United had him watched in virtually every single match last year. We are on the fence now. If Antonio says he wants to go to United and we get the right fee then the deal will be done.'
And last night the agent of Udinese's Chile striker Alexis Sanchez, 20, claimed he had been in talks with United.
Hot stuff: Chilean striker Sanchez is rumoured to be an Old Trafford target
Ronaldo's move to Real will not be completed until he returns from holiday in Los Angeles but the Spanish club have already been calculating how much he will be worth to them and believe his signing will make them the first to gross 500m euros in a year.
They are the five best footballers on the planet, according to FIFA ' and now just one plays in the Premier League. When Cristiano Ronaldo (centre) lined up in January with fellow nominees for the World Player of the Year award, it appeared to reflect the relative strengths of Europe's major leagues: Ronaldo and Fernando Torres (second left) from England, Xavi (far left) and Lionel Messi (second right) from Spain, and Kaka (far right) from Italy. But after Florentino Perez's return to RealMadrid, there has been a major shifttowards Spain. With Kaka and Ronaldo, who won the FIFA award, on their way to Madrid, four of the quintet will be playing in Spain. Premier League chiefs boast they offer the best in the world but after Manchester United's defeat by Barcelona and Real's transferspree, does anyone still believe them?
President Florentino Perez will renegotiate all existing sponsorship deals on the basis of adding Ronaldo to their signing of Kaka.
Each will be increased to such an extent that Madrid expect to be pulling in a total in excess of £425m annually by 2011.
Madrid's major sponsors are adidas, Coca-Cola, Audi, Spanish phone company Telefonica and Spain's biggest beer manufacturer Mahou.
Renegotiations: Perez is keen to glean new sponsorship deals following the acquisitions of Kaka and Ronaldo
All were preparing to reduce their financial commitment to the club, citing the economic crisis, but Real now expect a major U-turn especially from Adidas.
Madrid will be well rewarded for ensuring that Nike's most famous footballer now wears the logo of their biggest rival every weekend.
Perez said: 'We think can improve our accounts by aiming for three goals,' Perez said. 'Increasing ticket sales, increasing bank loans and increasing the club's economic value.'
He added that Real generated enough revenue to cover these massive transfer market investments, with more expected.
EXCLUSIVE: Fergie delight at Ronaldo as United chase Ribery and BenzemaDo players always go downhill after leaving Manchester United?MANCHESTER UNITED FC