The New York Stock Exchange said itwill cooperate with the Securities and Exchange Commission by
disclosing imbalances in market-on-close orders in 50 major
stocks thirty minutes prior to the close of trading Friday.
    The procedure will be followed this Friday when stock index
futures and options and individual stock options expire
simultaneously. Such triple expirations occur four times a year
and in the past have been associated with big swings in stock
market averages. In a new variation of the disclosure rules,
the NYSE said no market-on-close orders related to index
arbitrage can be entered after 1530 EST.
    The NYSE said all market-on-close orders for 50 big
capitalization stocks, including the 30 components of the Dow
Jones Industrial Average, must be entered by 1530 EST Friday.
The NYSE will then furnish to financial news services any
imbalance in market-on-close orders of 10,000 shares or more.
    After 1530 EST market-on-close orders in the 50 stocks can
be entered only on the opposite side of the imbalance. But the
bar on entering market-on-close orders related to index
arbitrage after 1530 EST is a new element of the disclosure
plan, which has the goal of making the market less volatile
during the triple expirations.
 Reuter
