NYSE Euronext added 30 companies, including shares of General Electric Co , M&T Bank Corp , Legg Mason Inc and General Motors Corp . Nasdaq OMX Group added 66 companies, including California First National Bancorp .

"We have been hearing from other companies and will update the list as necessary," said NYSE spokesman Scott Peterson.

The U.S. Securities and Exchange Commission, besieged by complaints that its initial list of 799 stocks issued on Friday had missed companies with major financial operations, decided over the weekend to let exchanges add to its list.

On Sunday, the NYSE asked its listed companies to inform the exchange if they fell in any of the categories listed by the SEC. Categories include banks, savings associations, broker-dealers, investment advisers and insurance companies.

The SEC emergency order against short sales in financial stocks will last through October 2. It may be extended further if the agency deems it necessary, but it can only last a total of 30 calendar days.

The SEC order followed similar action by the U.K. Financial Services Authority, which imposed a four-month ban on short-selling of financial stocks.

Other companies on the NYSE list include Capital One Financial Corp , Discover Financial Services and U.S.-traded shares of several Canadian banks, including Toronto Dominion Bank .

Earlier on Monday, the SEC granted limited relief to options market makers, who provide liquidity and ensure fair and orderly markets by continually posting prices at which they will buy and sell options.

Market makers will not be banned from short-selling stock covered under the emergency ban.

However, for new positions, market makers may not sell short when they know a customer is boosting a short position in shares of the financial firms covered under the emergency order.

(Reporting by Rachelle Younglai; Editing by Tim Dobbyn and Gerald E. McCormick)