José Mourinho, the former Chelsea manager, last night committed himself to Inter Milan until 2012 by signing a contract extension that could earn the Portuguese almost £15.4 million per year.

Mourinho, already the highest-paid coach in football, will be paid a gross salary of £13.9 million annually but incentives could push the figure higher.

The agreement ends the uncertainty over Mourinho’s future and guarantees the Inter coach a take-home salary of £7.9 million per year — a rise of more than £1.3 million. The self-proclaimed “Special One” signed a three-year deal last year when he arrived at the San Siro but speculation about Mourinho’s future has continued throughout a campaign in which Inter have progressed to their fourth successive Scudetto.

Real Madrid, in particular, have made increasingly covetous overtures to Mourinho. Florentino Pérez, the former president at the Bernabéu who is making a bid for re-election, has hinted that Mourinho would be his first choice to take charge at the club. This latest development will force the Spanish side to look elsewhere, however, as the new deal is not believed to contain a get-out clause.

Although Pérez has denied making an offer to Mourinho, the Inter coach maintains that he turned down an advance. “It is not easy because an offer like that makes you think twice,” Mourinho said. “But whoever guides Real Madrid will be fortunate because they will not be the first choice.”

If Inter can look forward to a period of stability, AC Milan, their city rivals, have a more confused outlook. Carlo Ancelotti is expected to leave to join Chelsea early next month, but Silvio Berlusconi, the Milan owner, has postponed any decision until after the final game of the season. The 3-2 defeat by Roma last Sunday meant that Milan have yet to seal an automatic Champions League place for next season. The result left Ancelotti’s side in third place in Serie A, level on points with Juventus in second, and facing a difficult trip to Fiorentina in their final match on Sunday.

Frank Rijkaard, the former Barcelona coach, has also been linked with the job at Stamford Bridge, but is believed to prefer to replace Ancelotti if the Milan coach goes to Chelsea.

Reports in the Netherlands say that Chelsea have beaten Inter in the race to sign Marko Arnautovic, the Twente and Austria winger. It was claimed that Arnautovic, 20, has authorised a deal to move to Stamford Bridge, but the two clubs have yet to agree a fee of up to £12 million.