The player met with club officials to agree compensation ahead of his expected transfer to the Portuguese club, but negotiations have hit a brick wall

Iker Casillas' exit to Porto has hit a snag after the goalkeeper and Real Madrid were unable to agree terms on a financial compensation package.

The Spain veteran has accepted a proposed contract from Porto worth €2.5 to 3 million a year after deciding to bring his long spell with the 2014 European champions to an end.

However, Goal understands the transfer cannot be rubber-stamped just yet as Casillas has failed to find an agreement with his current employers over compensation for the remaining two years on his current contract.

With no club willing to offer the 34-year-old the same €7m-per-season salary that he receives in the Spanish capital, Casillas has been forced into negotiations with los Blancos in order to make up the shortfall in his salary.

Madrid, however, have so far been unwilling to accept demands to pay the outstanding amount owed on his contract following discussions late on Thursday.

While the move to Porto is far from being called off, the impasse does throw Casillas and Madrid's plans into confusion, with the squad already having been summoned by new coach Rafa Benitez for the start of pre-season earlier on Thursday.

The goalkeeper had been keen to tie up his future prior to pre-season commitments, with last season's Liga runners-up officially beginning their preparations for the new campaign on Friday.

His agent, Santos Marquez, had earlier confirmed Casillas was happy with the package on offer from Porto.