Singapore's second-largest lender, United Overseas Bank, said quarterly profit fell a bigger-than-expected 5.1 percent, as volatile financial markets hurt non-interest income and as it wrote down bad debts.

UOB said on Friday July-September net profit fell to S$475 million ($323 million) from S$501 million a year ago. Analysts had predicted net profit of S$500 million, or a drop of 0.2 percent, from a year earlier, according to the average of four forecasts compiled by Reuters.

Loan growth in Singapore has so far defied expectations because of demand for construction and infrastructure projects, but analysts have warned that the double-digit growth is likely to slow in the months ahead as the economy cools.

UOB shares fell 9.8 percent in July-September, compared to an 11 percent drop in shares of sector leader DBS Group and a 12.2 percent decline in third-ranked Oversea-Chinese Banking Corp's.