Citigroup Inc., New York, expects to make $173 million in discretionary contributions to its U.S. pension plan this year, according to the firm's latest 8-K filing. The company also expects to contribute an additional $72 million to its non-U.S. plans this year. Citigroup contributed $400 million in 2004 to the U.S. pension plan to avoid an additional minimum liability, the filing stated. Shannon Bell, Citigroup spokeswoman, did not return calls for comment by press time. Citigroup had $9.4 billion in defined benefit assets as of Sept. 30, 2004, according to a Pensions & Investments estimate.