Bennetts Suzuki and team manager Jack Valentine have parted ways by mutual consent ahead of round seven of the MCE British Superbike championship at Thruxton.
Team owner Martin Halsall confirmed the split with immediate effect and he will take charge of his BSB squad during the interim period.
Halsall paid credit to the work Valentine has done for his team and says Halsall Racing is fully focused on the remainder of the 2015 BSB season with current riders Christian Iddon and Josh Waters.
"I'd like to thank Jack for his hard work and assistance with the Halsall Racing team and wish him the very best of luck for the future,” Halsall said. “While our season has not been easy, we have a solid structure in place for the second half of the year and we're looking to move further up the grid as we get towards the important showdown period, starting this weekend at Thruxton."
One of the series' best-known figures, Valentine has enjoyed a long career of team management both in the UK and on the world stage, most notably heading up Rizla Suzuki in BSB, plus Foggy Petronas and Worx Crescent Suzuki in WSBK.
Valentine and Halsall Racing have endured a turbulent relationship since 2013 when Valentine's involvement lasted just two rounds before a split.
The two resumed a working partnership in May 2014 under the Halsall Biker Gear Kawasaki banner, but since switching to Suzuki machinery at the beginning of the 2015 season the team has struggled, with its best result coming in the shape of Iddon's fifth place in race two of the season opener at Donington Park.