The Chicago Stock Exchange has become the first exchange to approve after-hours trading for institutional and individual investors. This move comes as other exchanges across the country work to extend stock trading into the late evening and early morning hours.

The nation's third largest stock market said it plans to add two extra hours of trading. Pending regulatory approval, it hopes to add the extra hours Oct. 1.

Both the Nasdaq Stock Market and the New York Stock Exchange are seeking to extend their hours as financial markets and electronic trading businesses offer added competition. But their plans to date have been slowed by what has been described as a failure to cooperate on exact hours for extending trading.

Late last week, the Chicago Exchange's board of governors approved a proposal to trade all S&P 100 and Nasdaq 100 issues between 4 and 6:30 p.m., EST. The Exchange also will allow limited trading of the 50 to 100 most-active non-S&P 100 and non-Nasdaq issues.