In contrast to the increased jobless rate, Manpower Inc.'s quarterly employment outlook survey shows that 17% of the county's largest businesses plan to increase their payrolls in the fourth quarter, while only 3% expect layoffs. The rest are undecided or expect no change. Three months ago, 9% of the firms foresaw new hiring and 6% predicted cutbacks. A year ago, 17% planned to expand while 20% expected layoffs . . . American Fastening Systems, a Camarillo-based distributor of industrial and construction supplies, leased an 11,000-square-foot headquarters facility on Pleasant Valley Road. The move represents a 50% expansion, according to brokerage Westcord/Westoaks Commercial Group . . . Dataproducts Corp.'s Americas Imaging Supplies unit completed a new 63,000-square-foot laser cartridge remanufacturing plant in Simi Valley.