"It's a great opportunity for me and I'll be playing for one of the biggest clubs in the world," said the 27-year-old.

"I had some great times at Roma but I've been waiting impatiently for this new chapter in my life," added Benatia.

Bayern said that the two clubs have agreed not to disclose the fee for the French-born centre-back, although Italian media reports estimated that Roma will receive around 30 million euros (�23.9m, $39.6m).

That would be made up of 26 million euros initially, with a further four million in potential bonuses.

"He has the necessary qualities to play for Bayern," added Bayern's sporting director Matthias Sammer.

The Bundesliga giants had been searching for defensive reinforcements after losing Javi Martinez until the end of the calendar year when he suffered a serious knee injury in the recent defeat to Borussia Dortmund in the German SuperCup.

In addition, Brazilian right-back Rafinha is out with an ankle injury and Bayern are also having to deal with the absences of Franck Ribery and Bastian Schweinsteiger.

He joined Roma last year from Udinese on a contract through to 2018.

Bayern began the new Bundesliga season with a 2-1 win against Wolfsburg last Friday. They travel to Schalke this Saturday.