SEOUL, May 18 (UPI) -- South Korean private equity firm, MBK Partners is stepping up its outreach efforts in the United States by recently hiring a lobbyist in Washington Korea Corporate Investment Holdings, or KCIH, retained Checkmate Government Relations as its lobbyist last month, according to the Office of the Clerk of the U.S. House of Representatives on Monday. KCIH is a special-purpose corporation established by MBK Partners for its takeover bid for Korea Zinc, the world's largest non-