The versatile striker has completed his move to St James' Park after the two clubs agreed an undisclosed fee.

A number of Premier League clubs had been linked with Smith after Sir Alex Ferguson hinted last month that he could be set to leave Old Trafford.

Smith has been unable to establish himself as a regular starter at United since joining from Leeds in 2004.

And with Ferguson strengthening his attacking options this summer and Carlos Tevez set to join, Smith could not be guaranteed a major role.

Sam Allardyce has won the race for the 26-year-old, beating off competition from the likes of Middlesbrough.

He will bolster a strikeforce at Newcastle which already includes players such as Michael Owen, Shola Ameobi and Obafemi Martins.

Smith will also be reunited with former Leeds team-mates Mark Viduka and James Milner.