Manchester United could lose Cristiano Ronaldo for a 'knockdown' £12 million in two years' time thanks to a ruling by the Court of Arbitration for Sport.

The CAS in Switzerland yesterday made a landmark ruling on Andy Webster's unilateral breach of contract from Heart of Midlothian in 2006.

The CAS decision, which also took a sideswipe at the handling of Webster's case by football's world governing body, Fifa, effectively enshrines a formula that allows a player to breach his contract after a "protected period" and pay his club only the value of his remaining wages in compensation.

It means Ronaldo, one of the hottest properties in world football, could theoretically walk away from Old Trafford in 2010, then aged 25 and arguably at his peak, for £12m. Cesc Fabregas could leave Arsenal in 2010, then aged 23, for a similar sum.