It will not be as easy as it once was for Chinese companies to list on the major U.S. exchanges, as the U.S. has set new rules to tighten standards for firms going public by reverse mergers. The U.S. Securities and Exchange Commission (SEC) last week approved new rules for initial public offerings (IPOs) of reverse merger firms on its three listing markets -- Nasdaq, NYSE, and NYSE Amex. The impact of the new rules remains to be seen, but the move will further slow the pace of Chinese companies going public in the United States, analysts said. \"The move largely aims to get candidates tested on the market before IPO approval, so it is hard to quantify how many Chinese firms will fail to meet the requirements,\" said Zhong Rixin, an analyst with Imeigu.com, a Beijing-based information provider on U.S. stock markets. Currently, stocks of more than 240 Chinese firms are traded on the three exchanges, and less than half were listed through reverse mergers, or mergers in which private firms buy large sums of shares of public firms, according to Zhong. Under the new rules, a reverse merger company applying to list is required to complete a one-year \"seasoning period\" by trading in the U.S. over-the-counter market or on another regulated U.S. or foreign exchange following the reverse merger, and to file all required reports with the SEC, including audited financial information. The company also has to maintain the requisite minimum share price for at least 30 of the 60 trading days immediately prior to its listing application and the exchange\'s decision to list.