Renato Sanches paid tribute to Benfica after the confirmation of his transfer to Bayern Munich on Tuesday.

The 18 year-old has signed a five-year contract with the Bundesliga champion and will join at the end of the season for $54 million - a fee which could rise to $123m depending on success-related bonuses.

Sanches expressed his pride at having secured a move to Bayern but insisted he remains fully focused on Benfica's quest for a domestic double, with the leader ending its domestic campaign against Nacional on Monday (AEST) before the Taca da Liga final against Maritimo next weekend.

"I want to thank all the Benfica supporters, all my family for this great moment in my life," he wrote via his official Instagram account. "I learned everything that I know today here so I have to thank Benfica and all those who helped me.

"[I'm] happy and proud to wear this new jersey of Bayern but we still have two finals ahead, I'm focused on the main objective, to win."