The semiconductor industry's leading indicator fell for a second month in February, a trade organization reported late today.

This week, the blue-chip indicator has fallen 162.42 points, erasing more than half of last week's 285-point gain.

The last time the indicator fell below 1 was in January 1991, when it hit 0.99.

This was the first time in 22 months that the indicator had fallen below 1.

Other, broader indicators have also fallen below levels they reached on the first trading day of the year.

The indicator fell amid extremely thin trading - 200 million shares.

The drop of 1.5 percent, to 2,480.70, was the biggest decline since the indicator fell 48.57, or 2.1 percent, to 2,292.14, on March 17.

Some indicators do not cleanly fall into the previous categories.

For the week, the key blue-chip indicator fell a cumulative 25.43 points.

For the week, the indicator fell 92.42 points, or 3.4 percent.