The 31-year-old, who is out of contract at Loftus Road at the end of the season, has made just four starts for Rangers since joining from Blackpool in the summer of 2011.
Campbell enjoyed a three-month loan spell at Ipswich earlier this season, scoring 10 goals, and he has also attracted the attention of Cardiff.
Bruce said: "We're talking to QPR. That's all we are doing at the moment, talking to them.
"We hope we can try and resolve something next week if we possibly can and we'll see what develops.
"I think the two chief executives are talking. Whether there's been a bid lodged just yet or not I'm not quite sure where we're up to."