Turbulence hits batch of U.S. stocks near the close

By Chuck Mikolajczak

NEW YORK (Reuters) - A cluster of stocks suffered from a bout of volatility near the closing bell on Tuesday in what may have been a mini-"flash crash" event, with the shares of over a dozen companies experiencing a sudden jump or fall in price and a spike in volume.

The flurry of activity occurred at 3:49 p.m. EDT (1949 GMT), with most of the affected stocks listed on the New York Stock Exchange, owned by IntercontinentalExchange Group Inc. The volatility caused moves of close to 5 percent in certain stocks, such as Nabors Industries Ltd.

Names such as Caterpillar Inc, Southwest Airlines Co and Western Union Co were among those affected. Among Nasdaq-listed names, the exchange's own stock, Nasdaq OMX Group Inc, was whipsawed.

The price moves did not trigger any volatility halts by the exchanges, which were put in place after the "flash crash" on May 6, 2010, when the Dow Jones industrial average lost hundreds of points in minutes before quickly rebounding. Those halts occur when the price of an individual stock moves 10 percent or more in a five-minute period.

The NYSE issued an alert after the closing bell that said it is reviewing trades in five stocks - AOL Inc, Nabors Industries, Marathon Petroleum Corp, Lorillard Inc and Canadian Natural Resources Ltd. Nasdaq OMX and Direct Edge also put out similar alerts, including those same five stocks and Nasdaq OMX's shares as well.

Representatives of the New York Stock Exchange and the Nasdaq declined to comment beyond the market alerts.

The exchanges later canceled all trades in AOL Inc executed at or below $33.17 between 3:49 p.m. (1949 GMT) and 3:51 (1951 GMT). Trades in Nabors Industries, Marathon Petroleum, Lorillard, Nasdaq OMX Group and Canadian Natural in the same time frame would stand, the exchanges said.

(Reporting by Chuck Mikolajczak and Rodrigo Campos; Editing by Jan Paschal)