Earnings at K-Swiss plummeted in the first quarter to $18 million or $0.51 per diluted share, compared with $24.9 million or $0.70 per diluted share in the first quarter of 2006. Revenues were down by 18.3 percent to $122.6 million from $150 million in the comparable quarter a year ago, with most of the slump coming from the U.S. market. The Westlake Village-based footwear marketer said its domestic revenues decreased 39.7 percent to $62.4 million in the first quarter while international revenues increased 29.2 percent to $60.2 million.