Sharp, who scored 56 goals in 95 appearances for the Iron, will spend the rest of the season at Rovers.
They have extended the loan stay of Wolves central defender Jason Shackell until the January transfer window.
The Danish striker Peter Lovenkrands has joined Newcastle. He was a free agent after being released by German side Schalke.
He netted three times in 12 appearances for the Magpies during a loan spell last season.
Queens Park Rangers have signed midfielder Ben Watson on loan from Wigan Athletic until the end of the year
Derby County have completed a swap deal to bring Lee Hendrie to the club from Sheffield United, with Jordan Stewart heading in the opposite direction.
Ipswich Town have wrapped up the signings of Sunderland pair Carlos Edwards and Grant Leadbitter for an undisclosed fee.
Blackpool have agreed a deal to sign former Fulham and Watford winger Hameur Bouazza on an initial one-year contract