"Werder want to achieve big things with me and I want to achieve them with Werder, so the situation is ideal," said the giant center-half.

Mertesacker joined Bremen from Hannover 96 in 2006, as he became one of the pillars of the Bundesliga side's defense.

The 23-year-old is also a key member of Joachim Loew's selection with the National Mannschaft, who will face Turkey in the EURO 2008 semis on Wednesday.