But by midmorning, an aggressive sell program pushed the market down 12 points.

An aggressive sell program in mid-morning pushed the market down 12 points.

Then, as computerized sell programs kicked in toward the end of the session, it headed down again before turning up a bit at the close.

As each sell program was tripped, it triggered two or three additional programs.

In all, the sell programs added 13.01 points to the day's loss.

Traders said that set off a wave of computer-triggered sell programs.

Most of the damage was exacerbated by sell programs particularly during the afternoon.

The decline was attributed mainly to the influence of computerized sell programs.

They may eventually offset one buy program with a sell program in another market.

The sell programs alone pulled the index down 42.28 points.