Peninsular & Oriental Steam Navigation Company Plc (P&O) said its ports business remained robust during the second quarter despite slower growth in world trade. But analysts said P&O's trading update confirmed its ports division's 10 percent internal growth for the quarter on a year ago was still below the company's target annual rate of 16 percent growth for the 12 months to December 31, 2001. P&O's ferries business found conditions tough in the quarter, raising the prospect that some analysts might trim full-year earnings forecasts on the back of less-than-expected ports growth and deteriorating ferries and container markets. "The ports business is showing some robust growth as they would say…