NEW YORK (Reuters) -New York Community Bancorp was sued on Tuesday by shareholders after the embattled lender posted unexpected commercial real estate loan losses and slashed its dividend, causing its stock price to sink to a nearly 27-year low. In a proposed class action filed in Brooklyn federal court, shareholders said the regional bank defrauded them by failing to disclose it would set aside more money for credit losses, and cut its dividend 71% to shore up its balance sheet. Led by Tennessee resident Walter Lemm, shareholders accused the bank of having inflated its stock price since last March by offering an "unrealistically positive assessment of the Company and its financial well-being and prospects."