NEW YORK (AP) The Nasdaq has shut down trading on one of its options markets, the latest technical problem to hit the exchange.

Nasdaq OMX said Friday it halted trading at 10:36 a.m. Eastern Time and announced at 2:10 p.m. that it would shut down options trading for the rest of the day. Regular stock trading on the Nasdaq Stock Exchange was not affected.

It was unclear when options trading would resume.

A stock option gives the holder the right, but not the obligation, to buy or sell a stock at a fixed price in the future.