The 28-year-old defender has signed a three-year contract at the Amsterdam ArenA in a deal worth 3million euros plus an extra 2.25million should they qualify for the Champions League during the next three seasons.

Oleguer becomes the club's fourth summer signing after Miralem Sulejmani, Dario Cvitanich and Ismael Aissati, but Van Basten is not done yet.

"We have another month before the transfer window closes," said the former Holland coach, who took over the Ajax reins on July 1.

"We will stay active in the coming weeks, just like we did in the past period."

Oleguer is looking forward to his new challenge in Holland after spending his entire career to date in his homeland.

"The sporting plans of the club and the new coach appealed to me enormously," the Catalonian added on www.ajax.nl.

"And Amsterdam is a terrific city. (Former Barca team-mate) Gabri told me good stories too. Ajax certainly was the best option to join.

"I will do my utmost to help the team. We must live from game to game. Hopefully we can then look back at the end of the season on a successful season."