"Everyone is sad and frustrated by this," Mosher tells GlobeSt.com.

Thorn and a retired business partner who lives in Phoenix have owned 100% of Mile High since 1997. In 1999, when Mosher left the Downtown Denver Partnership to join Mile High, he received a 20% stake in the company and Mike Sullivan, who heads the construction side on projects they develop, received 10%. But because of the partnership agreement, Mosher says he couldn't receive a bigger stake in the company, so he decided it was in his best interests to start his own company. Thorn says he will miss Mosher and they work well together. "I have nothing but respect for Bill," Thorn tells GlobeSt.com. Thorn adds that he spent two years trying to change the partnership agreement, but could not.

Among other things, Mile High developed the $200-million, 700,00-sf Wellington E. Webb Municipal Office Building. Some of Mile High's other developments include the 1.5 million-sf Colorado Center office and retail project at I-25 and South Colorado Boulevard, a 980-space Cultural Center Garage for the Denver Art Museum, and the 500,000-sf, Lakewood City Commons retail and government office center with Opus Northwest.

Mosher's new company is called Mosher Sullivan Development Partners and is headquartered in Manville Plaza. Tina Lashbrook, a construction project manager with Mile High, also has joined Mosher and Mike Sullivan in the new enterprise.

Mosher will continue to serve as the CEO of the Denver Convention Center Hotel Authority, which is in charge of building the $230-million 1,100-room Hyatt Regency hotel across from the Colorado Convention Center. "The contract was with Mile High, but they were hiring my services, so it was not a big issue," Mosher tells GlobeSt.com.

Both Thorn and Mosher say they hope they can work together in the future."If there's a joint venture opportunity and we could use George's and Mile High's expertise or George could use our expertise, certainly we would work together," Mosher tells GlobeSt.com.