(Reuters) - Brad Grey will step down as the chairman and chief executive officer of Viacom Inc's Paramount Pictures film studio, the company said on Wednesday.
Viacom is starting a search to identify a successor, and Grey, who headed Paramount Pictures for 12 years, will remain at the studio for a period to support the transition.
Viacom shares, which have gained about 25 percent this year, were down 0.5 percent at $44.46.
Grey's departure from the studio comes after years of underperformance, producing box office bombs such as "Teenage Mutant Ninja Turtles: Out of the Shadows" and "Ben-Hur."
The change in leadership follows a year of distractions for the studio as it was at the center of a bruising power struggle between Viacom's controlling shareholder, Sumner Redstone, and his daughter, Shari, and Viacom's former chief executive, Philippe Dauman.
The battle began when Dauman, who resigned in August, proposed selling a stake in Paramount against Redstone's wishes.
Last month, Grey helped to arrange a deal for two Chinese film companies, Shanghai Film Group (SFG) and Huahua Media, to invest $1 billion in Paramount, giving the studio much-needed cash and support as it attempts to grow.
As part of the agreement, SFG and Huahua Media will finance a combined 25 percent of all of Paramount's films for the next three years, with the option to extend to a fourth year. The Chinese studios will share in the economic returns of the films, but details were not provided.
During his tenure at Paramount, Grey was responsible for a seven-year marketing distribution deal with Marvel and the 2008 acquisition of DreamWorks SKG for $1.6 billion, from which Paramount got the Transformers franchise.
However in recent years, the studio has struggled.
Grey is the latest executive to leave Viacom Inc Chief Executive Officer Bob Bakish took over. In December, Denise Denson, the head of distribution for Viacom, left.
In January, longtime Viacom executive Doug Herzog, a 25-year veteran who oversaw Comedy Central and MTV, left. And last month, Michael Fricklas, general counsel, announced his departure.
On Friday, Reuters reported that Grey's departure was imminent.
Reporting by Jessica Toonkel and Saqib Iqbal Ahmed; Additional reporting by Anya George Tharakan; Editing by Anil D'Silva