A slowing economy combined with factors such as higher labor costs continue to stifle US enterprises operating in China, but optimism remains over the economic outlook and potential for a bilateral investment treaty.

According to a survey conducted by American Chamber of Commerce (AmCham) China in partnership with Bain & Company, US company revenues continued to grow in 2014, but not at the breakneck pace of previous years. More than 70 percent of respondents identified their organization as "profitable" or "very profitable."

"AmCham China member companies are committed to the market but continue to weather the challenging business environment," said AmCham China chairman James Zimmerman.

"Our companies appreciate the complexities and difficulties that the Chinese leadership is confronted with as it balances its economy and implements reforms. Nevertheless, much work lies ahead for all of us in 2015 and beyond as the Chinese economy continues to mature," Zimmerman added.

AmCham China member companies remain optimistic about the Chinese market because of sustained economic growth and an increase in domestic consumption, the survey, which was released on Wednesday, showed.

China's growing middle class and urbanization are also positive beacons for businesses. This year's report also reveals differences by sector, with service companies more optimistic than resource and industrial, it added.

Reforms such as the US-China Bilateral Investment Treaty (BIT) present a potential boon to business in China as companies look to overcome regulatory issues. More than two-thirds of respondents believe that the BIT would cut redtape, it showed.

AmCham China is a non-profit organization representing US companies and individuals doing business in China, with its membership comprising more than 1,000 companies.