Cotterill, who replaced Harry Redknapp at St Andrew's after a poor spell in the Championship, was presented at a press conference on Monday where the company set out their vision for the club.
The Blues have endured a six-year absence from the top flight, but Trillion Trophy Asia chief executive Ren Xuandong reiterated his support for the manager.
"We invested heavily in the summer and in the future we will back Steve Cotterill in the coming window in January and in the summer," Ren told reporters at the press conference.
"If it takes more investment for us to get to the Premier League, we will. If it takes a longer period of time for us to get back in there, we will."
Birmingham currently sit in the Championship relegation zone after just two wins from their 11 league outings this season.