WASHINGTON Ron Kirk, nominated as U.S. Trade Representative in the Obama administration, owes an estimated $10,000 in back taxes from earlier in the decade and has agreed to make his payments, the Senate Finance Committee said Monday. The committee said the taxes arise from Kirk's handling of speaking fees that he donated to his alma mater, and for his deduction of the full cost of season tickets to the Dallas Mavericks professional basketball team. The disclosure made the former Dallas mayor the latest in a string of top-level Obama administration appointees found to have underpaid their taxes, following Treasury Secretary Tim Geithner and Tom Daschle, who withdrew as candidate for Health and Human Services secretary. Nancy Killefer, Obama's pick for chief performance officer, also bowed out amid tax problems. White House spokesman Ben LaBolt said Kirk was working to clear up "a few minor issues" uncovered by the committee and expressed confidence he would be confirmed. Despite the error, Sen. Max Baucus, D-Mont., chairman of the Senate Finance Committee, issued a statement calling Kirk "the right person for this job," and said he would attempt to have the nomination moved through the panel quickly. Kirk routinely gave any speaking fees he earned to Austin College, the committee said, and did not list them on his tax returns. Instead, the committee said he should have listed the fees as income, then claimed them as charitable donations. The estimated effect was to reduce Kirk's tax bill by an estimated $5,800, according to the report. Kirk also deducted more than $17,000 as entertainment expenses for the cost of Mavericks' tickets. The committee said he substantiated about $9,900 of that amount, and will owe about $2,600 in taxes on the balance. The committee said that last fall, Kirk amended his income tax return for 2006, paying an additional $2,188 in tax and $139 in interest after a notification from the Internal Revenue Service. The return was filed by a paid tax preparer, the panel added.