Jacqui Dedo, who joined Covisint in December from Robert Bosch Corp., left the Internet upstart last week. She led Covisint's sales and customer enablement activities.
Dedo departed on her own accord and in good standing with the company, a Covisint spokesman said. No replacement has been named.
Dedo's exit comes at a critical juncture, as English, who took over May 1, has been meeting with suppliers and automakers around the world to win customers.
Since English arrived May 1, Covisint has added Peugeot as a minority partner and said it will sponsor a supplier portal for Delphi Automotive Systems Corp.
At Bosch, Dedo was president of the Ford Value Team, responsible for managing the company's global business with Ford Motor Co., including new business development.
English is scheduled to address the Management Briefing Seminars on Friday morning.
Covisint, the online exchange conceived and developed last year by Ford, General Motors and DaimlerChrysler, soon will lose two other key executives.
Rico Digirolamo, acting CFO, is returning to GM as soon as Covisint finds a replacement.
Digirolamo also served as acting Covisint CEO before English was hired.
Doug Van Daagens, senior vice president of business development, will return to Ford.
Covisint denied persistent rumors that Alice Miles, who was part of Covisint's development from the beginning, will return to Ford.
Miles officially joined Covisint in February and is senior vice president of global customer collaboration.
The changes indicate that English is putting his own management team in place, said Kevin Prouty, automotive research director at AMR Research, a company that provides e-business research and advice.
"He had no say in the selection of these people because he wasn't there," Prouty said. "He wants a team that is marching to his beat."
Covisint also is reviewing all of its technology partnerships to move faster in bringing more tools to the exchange, Prouty said.
"Both automakers and suppliers are pushing for more functionality on Covisint," Prouty said.
"Every day that Covisint is not rolling out something new, the suppliers are doing it on their own."
Covisint is considering adding MatrixOne Inc., a technology company that offers software to better connect automakers and suppliers with their supply chains.
Covisint is trying to adopt the mindset of a supplier rather than of an automaker, said Ray Bernard, director of automotive sales at Oracle Corp., a Covisint technology partner.
"They're kind of changing gears now," Bernard said. "They've come to the reality that they don't have that Tier 1 mindset."
Bernard said if the company can think like a Tier 1 supplier, it will be better able to convey the value of Covisint to its potential customers.