U.S. stock and options markets will be closed on Monday, and possibly Tuesday, as regulators, exchanges, and brokers worry about the integrity of markets and the safety of employees in the face of Hurricane Sandy.

Market participants and regulators decided late on Sunday to shut the market, reversing a plan to keep electronic trading going on Monday. Bond markets will remain open, but will close at noon, a trade group said.

The decision to close stock and options markets came after regulators, exchanges, and dealers discussed the unknowns that would have been tested if the markets opened on Monday, three sources familiar with the situation said.

For example, NYSE Euronext's New York Stock Exchange had initially planned to shut its physical trading floor, which would have meant operating as an all-electronic exchange for the first time.

The decision to shut down the stock markets came after Wall Street had prepared to open for business on Monday with limited staffing after a mass transit shut-down in New York, booking hotel rooms for key employees and leaning on offices in other cities.

Read it at Reuters.