The girlband were approached to release the charity track after holding a secret meeting in London to discuss their reunion plans.
"The plan is to release it in November," a source told The Sun.
"It is looking like it will be an original song. Bosses think it will be the perfect comeback hit as well as helping a good cause."
The new single is reportedly part of the group's plan to celebrate their tenth anniversary at the end of the year. They are expected to tour in early 2013, while Kimberley Walsh has also teased a new album.
Girls Aloud previously recorded 'I'll Stand by You' in 2004 as the official Children In Need single.
An announcement regarding their comeback will be made "very soon", according to Cheryl Cole.
Watch Girls Aloud's video for 'I'll Stand By You' below: