Also. . .

* Polk Audio Inc., a maker of loudspeaker systems, announced plans to go private, citing a small shareholder base and low trading activity. The Baltimore-based company also said Asia’s economic problems have hurt the industry.

* Interim Services Inc., a provider of staffing services, agreed to buy rival Norrell Corp. for about $498 million in stock as a capstone to its North American expansion. Interim said it will pay 0.9 of a share for each Norrell share in the deal and will assume about $55 million in debt.

* An investment group led by Edward W. Rose III acquired a 7.6% stake in North Face Inc. and urged the maker of outerwear and camping gear to complete a shareholder buyout it has withdrawn.