Most brokers said they agreed with the Big Board's decision to limit trading over the next few days despite the possibility that it might heighten the crisis atmosphere.

Large businesses would benefit from the replacement of "unnecessarily restrictive" rules that seek to limit trading by issuers and underwriters during a securities offering, the report said.

In fact, they are often warned weeks in advance that an exchange may limit trading.

The Dodd-Frank Act included the Volcker Rule, which among other things limited proprietary trading by banks and their affiliates.

As futures and options markets began to limit or halt trading, more investors who wanted to sell turned to the stock market.

The exchange has already limited dual trading in its biggest trading pit, that for Standard & Poor's 500 stock-index futures.

He said that in a few weeks the commission would consider a package of proposals to limit late trading and improper market timing in mutual funds.

Each country agreed to refrain from trading in the other's territory, and both countries agreed to limit trading to their own possessions.

The Alliance technology fund says only that it reserves the right to limit trading in its fund shares.

To reduce their own risk, such brokers require their clearing clients to keep funds on deposit as collateral, and they can limit trading.