rachhaydensplit.jpgHayden Christensen and his fiance Rachel Bilson are cooling things off ... at least for now, according to UsMagazine.com.

The two have been engaged since February 2009 but now, they're "taking a break."

Just last night, Bilson, 28, walked the red carpet of the Take No Prisoners event without her engagement ring.

According to the mag, when asked about her upcoming wedding plans, she replied while pointing to her bare hand, "No, no plans. No nothing."

A source also says that Christensen and Bilson are "taking a month off" and will decide after that whether their engagement will continue.