Leadbitter, 23, has made just two appearances for Sunderland this season while Edwards has appeared just once.
Keane is looking to bolster his squad after a poor start to their Championship campaign.
Matthew Buck of the Professional Footballers' Association, who represents Leadbitter, told the East Anglian Daily Times he was waiting for developments.
"We have been given permission to open talks with Ipswich. We're heading for talks now and will see what happens," he said.