Complex sentence: Ajdarević used a contractual clause that allowed him to find another club after the 2010 season had ended and despite Örebro SK's attempt to keep him by offering a new contract, IFK Norrköping managed to sign a long-term deal with the midfielder.
Split into simpler sentences: Ajdarević used a contractual clause that allowed him to find another club after the 2010 season had ended. Even though Örebro SK tried to sign him on a new deal, IFK Norrköping managed to sign a long-term deal with the midfielder.