Citigroup Inc., which last week ousted Chief Executive Officer Vikram Pandit over management missteps, is staging a comeback in corporate-bond underwriting as it helps overseas companies borrow in the U.S.

Citigroup, the top underwriter of bond sales worldwide in the decade before the 2008 financial crisis, managed 6.1 percent of sales this year through yesterday, up from 5.7 percent in 2011, according to data compiled by Bloomberg that excludes self-led deals. The New York-based lender climbed to second in rankings from fourth last year, closing in on JPMorgan Chase & Co. and relegating Bank of America Corp. to third.

From Asia to the U.S., issuance of corporate bonds totals $3.2 trillion this year, second only to 2009's pace, as central banks led by the Federal Reserve cut interest rates to record lows and investors seek riskier assets. Citigroup's global reach has helped it win underwriting business from companies including Heineken NV and Nippon Life Insurance Co. looking to tap U.S. markets amid unprecedented demand for dollar-denominated assets.