Eleven members of Congress asked the US Securities and Exchange Commission on Monday to stop the sale of the Chicago Stock Exchange to a group led by China-based investors, saying the regulator lacks the ability to monitor the foreign buyers, Reuters reports. The proposal to sell privately owned CHX for an undisclosed amount to a consortium led by Chongqing Casin Enterprise Group (CCEG) has drawn attention because it would be the first time a US exchange has been bought by Chinese investors. There are also US investors in the group. “With little or no insight and transparency into government-dominated Chinese markets, the SEC will be unable to monitor the ownership structure of CCEG after approval, leaving CHX open to undue, improper, and possibly state-driven influence,” the Republican and Democratic lawmakers said in a letter to the SEC. The SEC said in early June it would take up to another 60 days to make a decision on the sale.