“It will give me the opportunity to play on an international level in a European top club,” wrote Podolski on his Facebook page.
Podolski joined struggling Cologne – currently 16th in the Bundesliga - from Bayern Munich in 2009. The 26-year-old striker said his decision was not a choice against Cologne, “but for this great chance in my sporting career.”
“We regret his decision very much,” club chairman Claus Horstmann told the Kölner Stadt-Anzeiger newspaper on Monday. “We had been prepared for a competitive offer and would have liked to extend the contract with Lukas Podolski on this basis.”
Horstmann went on to thank the star striker for the “many great football moments in Cologne” which had helped raise the profile of the club in the past years.
Arsenal reportedly paid Cologne €13 million for the striker whose contract had been set to run until 2013 according to a report in the Bild newspaper on Monday.
The club said the transfer fee would be invested in helping improve the quality of the professional team and promoting younger players.
Podolski first joined Cologne's junior team at the age of ten and played his debut game in the Bundesliga with the club in 2003 when he was eighteen.
In an emotional farewell on Facebook, Podolski wrote that the decision had not been easy, as the club, the fans and the city are “very special” to him. “I'll always keep the club in my heart” he wrote.