UPDATE: NBC made it official with a release on March 20, announcing that The Sing-Off will be back as a holiday strip later this year.
NBC is bringing back The Sing-Off for a fourth season, The Hollywood Reporter confirms.
It has been a year and a half since the a capella competition series has been on the year, after wrapping up its third-season run in November 2011 to modest ratings.
An official casting website launched Wednesday, announcing an open search and listing four cities that will take part in the audition process (Nashville, Chicago, Los Angeles and New York City) beginning April 27.
The Sing-Off ran for three seasons starting in December 2009, and was hosted by 98 Degrees' Nick Lachey and judged by Ben Folds, Boyz II Men's Shawn Stockman and Sara Bareilles. (Nicole Scherzinger was a judge for the first two seasons before Bareilles took over.)
A capella group Pentatonix won the most recent effort, and their debut album PTX Volume 1 broke into the top 15 on the Billboard 200.
Other details, including the host and judging panel, were not available.
The news comes on the heels of the success of big-screen music drama Pitch Perfect, which made $109 million in total box office.