SEATTLE -- Microsoft chairman Bill Gates, the second-wealthiest American with a net worth of $6.1 billion, said in an interview published this week that ultimately he will give away 95 percent of his vast fortune. Gates, 38, told Playboy magazine that he plans to give the money away when he is in his 50s to charitable and scientific organizations, leaving a "modest amount" of perhaps $10 million to any children he might have. But he warned that his fortune is mostly on paper. "Remember, I don't own dollars," he said. "I own Microsoft stock. So it's only through multiplication that you convert what I own into some scary number."Gates, in the wide-ranging interview, said he plans to continue in his role as chief executive of the computer-software company for at least a decade, after which he would expect to pass the daily responsibility of running the company to a younger person. Despite the fact that Microsoft is by far the largest producer of software for personal computers, Gates said he continues to worry about competition. "In this business, by the time you realize you're in trouble, it's too late to save yourself," he said. "Unless you're running all the time, you're gone."But he emphatically denied, as he has in the past, that Microsoft has in any way abused its position in the industry to the detriment of its competitors, the subject of an ongoing U.S. Justice Department inquiry. "Whenever a company is successful, people say it's out to dominate," he said. "We're actually more open than any other company that has multiple products. We take lots of affirmative steps to help other companies."