Navistar International Corp., Warrenville, Ill., will contribute a total of $231 million to its North American pension plans in 2004, up from the $162 million it forecast on Oct. 31, the end of the fiscal year. The company has already contributed $77 million to the plans as of April 30, Navistar said in its second quarter SEC filing, submitted today. The increase in this year's total contribution eliminates the need for required contributions in 2005 and will greatly reduce what will be required in 2006, said Ron Wiley, spokesman. Navistar reported total North American pension plan assets of $2.99 billion on Oct. 31, and total liabilities of $3.98 billion, according to its annual report. Mr. Wiley declined to specify the number of plans Navistar sponsors; the Money Market Directory lists two U.S. defined benefit plans and two U.S. 401(k) plans.