Nearly one out of four listed companies with annual sales of 1 trillion won (US$974 million) or more were unable to cover interest payments with their earnings last year as a sluggish domestic market hurt their profitability, data showed Wednesday. According to Chaebul.com, which tracks the nation's top conglomerates, 36 firms, or 23 percent, out of 159 companies that logged annual sales of 1 trillion won or more reported an interest coverage ratio of below 1 last year.