The Los Angeles Business Journal’s index of largest local public companies dropped nearly 4 percent for the week ended Aug. 12 as investors remained nervous about the prospect of another recession.

The weighted LABJ index, which last week ended the week down 9.5 percent, lost another 3.8 percent to close at 107.83. Decliners outpaced gainers 126 to 42 and 12 companies were unchanged.

One of the largest decliners was PC Mall Inc. which dropped 23 percent to $5.91. The Torrance direct technology marketer said that its expansion into “daily deal” online marketing had moved into its beta phase in Los Angeles and two other markets.

THQ Inc. fell 19 percent to $1.85. The Agoura Hills video game publisher announced a restructuring program that included significant layoffs.

K-Swiss Inc. fell nearly 15 percent to $6.49. The Westlake Village casual shoe and sneaker company reported disappointing second quarter earnings and was downgraded by an analyst.

Among the biggest gainers was Staar Surgical Co., which continued to benefit from last week’s upbeat second quarter earnings report. The Monrovia maker of implantable eye lens jumped 24 percent to $6.74.

Rentech Inc. rose 13 percent to 99 cents. The Los Angeles alternative energy company reported better than expected earnings and revenue in its fiscal third quarter.

Demand Media Inc. gained 8 percent to $9.15. Despite a larger second quarter loss, the Santa Monica operator of eHow.com and other specialty web sites reported better-than-expected sales, renewed a key agreement with search engine Google and announced two acquisitions.