Hewlett-Packard Co. reported sales and profit fell in the last quarter, and its stock slipped further in late trading Thursday after the giant computer-maker issued a forecast for the October quarter that was lower than Wall Street expected. The results showed HP is still struggling with a host of challenges as it prepares to split into two companies later this year. HP reported net income of $854 million for its fiscal third quarter, down 13 percent from a year earlier, as sales fell 8 percent to $25.35 billion. The company has seen year-over-year revenue declines in all but one quarter for the last four years. Earnings for the quarter, which ended July 31, were slightly better than Wall Street estimates. HP said its earnings amounted to 47 cents per diluted share, or 88 cents per diluted share after adjusting for one-time gains and costs.