Moody's Investors Service changed to stable from negative the outlook of its Ba1 senior unsecured debt rating and (P)Ba1 Japanese shelf registration rating of Mitsui O.S.K. Lines, Ltd. (MOL) and Ba1 debt ratings of Euromol B.V. and Mitsui O.S.K. Finance plc. The latter two companies are MOL's overseas finance subsidiaries supported by keepwell agreements with MOL. This rating outlook change is based on Moody's belief that MOL's improving performance will continue to contribute to its earnings and the company's financial fundamentals will be strengthened in the near to medium term. Although MOL's debt level increased marginally after its April 1999 merger with Navix Line…