Shoe manufacturer K-Swiss Inc. saw a small drop in its net earnings for the third quarter following the underperformance in the domestic market, the company reported Thursday. The Westlake Village-based company reported earnings of $20.9 million, or $0.59 per diluted share, on worldwide revenues of $133.3 million for the quarter ending Sept. 30. That is a slight decrease from third quarter 2005, when the company had net earnings of $21 million, or $0.59 per diluted share, on worldwide revenues of $136.6 million. Domestic futures orders with ship dates of October through March decreased by 32 percent to $92.9 million by the end of the third quarter. For the third quarter in 2005, the company had domestic futures orders of $136.6 million. The underperformance of domestic business and continued momentum in the international business was consistent with company forecasts, said company Chairman of the Board and President Steven Nichols, in a prepared statement released Thursday. “We were able to supplement the strength in revenues and backlog in Europe and Asia with better-than-expected margins and at-once order of our Classic products,” Nichols said. “However, the decline in the domestic backlog was much larger than we had anticipated.”