(AP) The New York Stock Exchange will close its trading floor Monday as Hurricane Sandy barrels its way up the Northeast, but Big Board trading will continue electronically.

NYSE Euronext said Sunday it is putting in place its contingency plans beginning Monday and will announce later when the trading floor will reopen.

The New York Mercantile Exchange, a commodity futures exchange, also will be shutting on Monday its trading floor which is located in a mandatory evacuation zone. The CME Group, which owns NYMEX, said all electronic markets will open at their regularly scheduled times.

The moves come as Hurricane Sandy causes the shutdown of transportation systems throughout the region. Governor Andrew Cuomo said New York City's subways and buses will shut down Sunday evening. New York City Mayor Michael Bloomberg ordered residents to evacuate some low-lying areas Sunday and said city public schools will close Monday.

Even if Hurricane Sandy knocks out power for lower Manhattan, the NYSE can switch to its backup power generators for electricity. The servers that handle the exchange's transactions are housed in Mahwah, N.J.

Trading has rarely stopped for weather. A blizzard led to a late start and an early close on Jan. 8, 1996, according to the exchange's parent company, NYSE Euronext. The NYSE shut down on March 27, 1985 for Hurricane Gloria.

Since the Great Depression, the longest suspension in trading at the NYSE occurred after the attacks on the World Trade Center on Sept. 11, 2011, when the exchange closed for four days.