By Spain correspondent Miguel de Souza

Real Madrid have slapped a £50million price tag on Sergio Ramos after rejecting Manchester United’s opening bid for the unsettled defender, Football Insider sources understand.

United have tabled a formal offer of around £35m for Ramos after learning that the 29-year-old feels undervalued at the Bernabeu.

The Spain international met with Real officials on Wednesday morning and, according to Spanish reports, did not give the club any assurances that he wanted to stay.

There is now a growing sense that Ramos wants to quit the 10-times Champions League winners.

This encouraged United to make a bid of around £35m for the versatile defender although Spanish sources have told Football Insider that Real value the player at the £50m mark.

New Real manager Rafael Benitez is keen to keep hold of Ramos and has told the board that all offers for the player this summer should be rejected.

United registered their interest in the Spain international after learning of his growing tensions with the Spanish giants in the wake of his stalled contract talks with the club.

Football Insider understands that the Premier League club have discussed Ramos with Real during talks about the proposed transfer of David de Gea to Madrid.

United accept that the departure of De Gea to Real is inevitable but want a leading player from the Spanish club in return, although the two deals would be independent of one another.

It would be regarded as one of the most sensational deals of the summer if United could entice Ramos given his elevated status both at the Bernabeu and as a senior member of the Spain squad that has dominated world football for the last decade.

Ramos, who has been at Real for 10 seasons and is the vice-captain, has just two years remaining on his contract and has failed to reach agreement with the club on a contract extension.

United are wary that the defender is using interest from Europe’s leading clubs to engineer a more lucrative offer from the club he joined from Sevilla in 2005.

The Barcelona presidential candidate, Jordi Majo, claimed he had been indirectly offered Ramos last week. Real Madrid did not deny that story but the player’s camp did.