Vaughan will follow Manchester United pair Wes Brown and John O'Shea, who both signed for the Black Cats yesterday.

Gibson had been expected to be the most likely of the United trio to join Sunderland, but the signing of creative midfielder Vaughan on a free and the arrivals of Seb Larsson and Craig Gardner have forced both parties to cool their interest in a deal.

Stoke retain an interest in the Republic of Ireland midfielder, who has been told he can leave Old Trafford.

Brown and O'Shea are Steve Bruce's seventh and eighth summer signings after Ahmed Elmohamady, Connor Wickham, Gardner, Ji Dong-Won, Keiren Westwood and Larsson.

Bruce said: "We are delighted to welcome a player of Wes' ability, experience and character to the club.

"He has been a fantastic professional for Manchester United through the years and not only will he strengthen our defensive options, he will also bring with him a winning mentality and level of maturity which can only be positive for the players around him."

United boss Sir Alex Ferguson admitted it had been a tough decision to allow Brown to leave the club.

He said: "Wes has been a great asset to the club during the most successful period in its history.

"He was a product of the youth system and marked himself out from an early age as one of his generation's most natural defenders.

"In his time with us, he certainly became a favourite with the fans for his no-nonsense approach to the game and his infectious personality.

"It's always the hardest of decisions to let loyal servants go. But life moves on and, unquestionably, Wes will get the chance to make a real contribution to Steve Bruce's Sunderland, and I'm delighted to be passing him into such good hands.

"Everyone connected with United wishes him a long and happy stay at Sunderland."

New boy O'Shea said: "Once I'd heard reports about the club and the people here, the ambitions and what the manager was all about it was the only place I was going to come to."

And Bruce said: "John has been a solid, consistent part of Manchester United's squad for well over a decade which goes to show the fantastic pedigree of player we have signed.

"He is a wonderful professional both on and off the field and his wealth of experience and versatility will be great attributes for us. I'm delighted with the players we've been able to secure ahead of the new season."

Brown, 31, made senior 361 appearances for United over 15 years as a professional having joining the club as a 12-year-old, and has five Premier League winners' medals.

He won 23 England caps before announcing his retirement from the international game last summer.

He will bring a welcome versatility and vast experience to the Stadium of Light, where his arrival will go some of the way to making up for the loss of loan signings Nedum Onuoha and John Mensah.

Ostensibly a central defender, he can also play at right-back and with O'Shea equally comfortable across the back four as well as in midfield, Bruce could have healthy options at the back next season.

O'Shea has been one of Ferguson's most reliable lieutenants in his 13-year career at Old Trafford.

He broke into the first team in 2001-02 and became a solid performer in each season since. The Republic of Ireland international has played in every single position for United, even in goal.

Both O'Shea and Brown have signed four-year deals for undisclosed fees.

Meanwhile, Sunderland have appointed Bryan "Pop" Robson as their new chief scout.

The Sunderland-born former striker, who returns to Wearside from his last post as an international scout for Chelsea, played 174 times for the club during three spells, served as reserve-team coach and Academy director and even stood in as caretaker manager.

He said: "Sunderland is obviously a club very close to my heart. I had great times here both as a player and as a coach, so I'm thrilled to be back working with Steve Bruce and his excellent management team."