The 24-year-old was the subject of two previous bids by Rafa Benitez’s side, with offers of £3.5m and £4.5m turned down by Rovers.
But captain and player of the year Hanley is now set to depart for St James Park after a third offer was agreed on by both parties.
Hanley is set to sign a five-year contract at St James Park and would become Benitez’s sixth summer signing in the North East as he looks to lead the Magpies back into the Premier League at the first time of asking following their relegation from the top flight in May, joining goalkeeper Matz Sels, defenders Jesus Gamez and Isaac Hayden, midfielder Matt Ritchie and striker Dwight Gayle in the black and white.
The centre-half, who has two years left on his Rovers contract, has been the source of speculation about his future all summer and was linked with Fulham at the end of last season.
Hanley travelled to Austria with the Rovers squad for their pre-season training camp, but sat out the game against SV Ried with a knee injury and has not featured in the three matches since, including last night’s 1-1 at Rochdale.
He has made 200 appearances at Ewood Park after joining the club as a 16-year-old from Crewe Alexandra.
Coyle said last week that he didn’t want to lose his skipper, but the decision was ultimately out of his hands.
He added: “I know the way the world works when agents get to work and such forth.
“But all I would say is Grant Hanley’s our captain and we don’t want to lose him.
“I totally understand why Newcastle covet him but, as I said before, and I’ll repeat it, in my opinion they are nowhere near the valuation which I consider Grant Hanley to be.”