The 23-year-old will join Chelsea at the end of the season after agreeing terms and German magazine Sport-Bild report he has signed a five-year deal to keep him at Stamford Bridge until 2017 for an undisclosed fee.
"Chelsea is my dream club," the winger told Sport-Bild.
"I'm happy that I get the chance to play for them. It is a challenge for me.
"Tottenham Hotspur were also interested, but I opted for Chelsea, because they suit me well."
Marin has 16 caps for Germany and played twice at the 2010 World Cup, coming on as a substitute in matches against Australia and Serbia, but has not played for the national team since November 2010.
He is not expected to be included in Joachim Loew's squad for Euro 2012, set to be named on May 7, with the tournament to start on June 8.
Marin joined Bremen from Borussia Moenchengladbach for 8.5 million euros in 2009.
Source: AFP
Source: AFP