"We are very happy that Per has committed himself to a move to Werder Bremen and we that we were able to meet an agreement with Hanover 96," General manager Klaus Allofs told Werder Bremen's official website.

Bremen made a 5 million Euro offer for the 21-year-old, and Allofs is confident that the World Cup player will make a strong addition to the team.

"Per has developed very quickly in the past few years and we are certain that he'll find exactly the right conditions with us to go even further," he said.

In his three years of the Bundesliga, Mertesacker scored seven goals in 74 games, and played 29 times internationally.

Coach Thomas Schaaf was delighted by the acquisition and said that the young player was a World Cup favorite and has huge potential to grow.

"Per made himself a real hero for the fans during the World Cup with the style in which he plays," he said.

"Whoever can play such a convincing World Cup at such a young age will be able to strengthen our squad right from the start."

While Werder Bremen prepares to welcome its new player, they also must say goodbye to Frank Fahrenhorst.

The 28-year-old defender received a three year contract with Hanover 96 as a part of the exchange.