Butt set to replace Speed at Newcastle.
The 24-year-old replaced Chelsea's Paulo Ferreira in the Portugal team at Euro 2004, and was impressive as the hosts reached the final.
Butt landed in Manchester shortly before 8am yesterday and is expected to travel to Tyneside today for a medical and discuss personal terms.
'Newcastle United have agreed terms for the transfer of Nicky Butt from Manchester United, pending a medical and personal terms,' a club spokesman said.
Butt would replace 34-year-old Gary Speed, who left the Magpies for Bolton in a pounds 750,000 move last week. The club have also allowed another midfielder, Hugo Viana, to return to Sporting Lisbon.
Butt won one Champions League title, six Premier titles and two FA Cups in 13 years with the Red Devils.