The Girls Aloud singer announced her engagement to the American footballer in September, describing their relationship as "really, really nice" and "very different".
However, Coyle took to Twitter tonight to confirm that she is no longer with Bell, although she insisted that the two parted on amicable terms.
"A few weeks ago Jason and i broke up (sic)," Coyle wrote. "We are great friends and decided we are better this way. Im in NYC working & I love all your support.x"
It was recently reported that Coyle had decided to delay her wedding until after the ceremony of Girls Aloud bandmate Sarah Harding, who got engaged to DJ Tom Crane on New Year's Day.
An insider had then claimed that Coyle wasn't "in the right mindset to organize a wedding".
Nadine Coyle- Runnin' by FreedomDevelopment
