'Love You More' - described in a press release as "a soulful ballad which sees the boys demonstrating their smooth R&B vocals with tender, heartfelt lyrics" - will be released on November 14.
It will also appear on the group's upcoming sophomore album, Outta This World, which is scheduled for release on November 22.
The album, the follow-up to their million-selling debut, features production from Jerry Wonder, Toby Gad and Stargate.
Its lead single, 'The Club Is Alive', recently became the group's third UK No.1 single in four attempts.
Previous Children In Need singles have been recorded by artists including Girls Aloud, Spice Girls and Will Young. Peter Kay scored the fifth Children In Need chart-topper with last year's effort, a special medley accompanied by an animated video uniting a variety of BBC cartoon characters.
The 'Love You More' cover art appears below: