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.
However, with owner and chairman Ellis Short determined to establish the club in the top half of the Premier League, they are doing all they can to reach agreement over a man O'Neill hopes can provide a focal point for his new-look side.
Fraizer Campbell, Ji Dong-won, Connor Wickham and youngster Ryan Noble represent Sunderland's current attacking options but proven top-flight experience and goals, both of which Fletcher can offer, are in short supply.
The Black Cats finished in 13th place last season after successfully fighting their way out of the scrap at the foot of the table, where they found themselves on O'Neill's arrival in December.
To date, they have made just one summer signing, bringing in free agent Carlos Cuellar following the expiry of his contract at Aston Villa.
Source: PA
Source: PA