However, it is understood the two clubs are locked in talks over the 25-year-old Scotland international, who is Black Cats boss Martin O'Neill's number one target this summer.
Wolves' chief executive Jez Moxey told the Express and Star: "Rumours that we have accepted a bid from Sunderland are incorrect. They want the player, but we haven't accepted anything."
Moxey recently indicated that the Black Country club are desperate to retain all their big-name players in an attempt to win an immediate return to the Barclays Premier League.
However, Sunderland are equally keen to bolster their striking options, with manager Martin O'Neill having seen Nicklas Bendtner return to Arsenal following his loan spell and Asamoah Gyan complete a permanent switch to United Arab Emirates club Al-Ain.
To date, the Wearside outfit have been unable to come up with a deal to satisfy Fletcher's current employers with the manager admitting last week that his efforts to strengthen his squad have stalled somewhat.