Bautista joined Ducati this season after losing his place on the MotoGP grid at the end of last year, and dominated the opening half of the season on the new Panigale V4 R with 11 race wins on the bounce.
However, a string of crashes at Jerez, Misano, Donington and Laguna Seca has seen him drop 81 points behind Kawasaki’s Jonathan Rea.
Bautista looked set to re-sign with Ducati for next year, but negotiations stalled and rumours of a switch to Honda soon surfaced.
Speaking to Motorsport.com during the British Grand Prix weekend, Ciabatti confirmed Bautista had agreed a two-year deal with a “rival manufacturer” and negotiations with Redding are “well advanced”.
“We know that Alvaro has accepted an offer from another manufacturer for the next two seasons,” he said. “We are well advanced in negotiations with Scott, so hopefully it can be announced in the next few days.”
Redding currently rides a Paul Bird-run Ducati V4 R in the British SuperBike Championship, with five wins putting him at the head of the standings up until last weekend’s Cadwell Park round, when he relinquished the lead to teammate Josh Brookes.
The 2013 Moto2 runner-up and former Pramac Ducati rider also lost his MotoGP seat at the end of last season following a difficult campaign with Aprilia.
Redding will partner Chaz Davies at Ducati in his debut WSBK season, while the second Honda spot could go to current Honda BSB rider Xavi Fores or Alex Lowes – whose place at Yamaha is likely to be taken over by Toprak Razgatlioglu.
Lowes has also been linked to the soon-to-be-vacant Puccetti Kawasaki currently occupied by Razgatlioglu, while the factory Kawasaki line-up of Rea and Leon Haslam looks set to remain intact next year.