A judge ruled at Manchester Mercantile Court in July last year that the agreement between sports management firm Proactive and Rooney for a 20 per cent commission for a number of deals was unenforceable.
The judge added that the eight-year contract Rooney signed as a young Everton player was "an unreasonable restraint" of his trade when the Football Association recommended a maximum of two years.
But appeal judge Lord Justice Alan Ward said Monday that Proactive did have a prospect of success in its arguments over Rooney's contract
"The mere fact that this was a claim for millions of pounds is almost in itself a compelling reason to give permission to appeal," Ward said.
The original verdict was postponed until after Rooney's participation in England's ill-fated World Cup campaign in South Africa last year.
That saw a firm owned by Rooney's wife Coleen ordered to pay Proactive just over £90,000 pounds ($138,227) for work conducted on her behalf up to October 2008.
Proactive took the couple to court, claiming they had withheld the commission on multi-million pound deals brokered during the time they represented him.
Rooney made no payments after football agent Paul Stretford, a director and founder of Proactive, left the firm in October 2008 taking with him the England forward as his star client.
Rooney was signed by Stretford for Proactive in 2002 when he was still playing for Everton and the teenage striker quickly garnered multi-million sponsorship deals with companies including Nike, Coca-Cola and EA Sports.
Proactive argued that, as such contracts for Rooney and Coleen were brokered by Stretford while he was still at the firm, they were due the 20 percent commission amounting to 4.3 million pounds.
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