Citigroup Inc. posted a $5.11 billion loss for the three months ended March 31, less than analysts’ most pessimistic estimates, sending shares of the biggest U.S. bank by assets up as much as 7 percent in New York trading. The company said it plans to cut 9,000 more jobs, Bloomberg reported.

The first-quarter net loss of $1.02 a share compared favorably with the $1.66 loss predicted by Merrill Lynch & Co. Inc.’s Guy Moszkowksi, Institutional Investor’s top-rated brokerage analyst. Citigroup reported almost $16 billion in write-downs and increased bad loan reserves as customers fell behind on home, car and credit-card payments. Moszkowski had predicted an $18 billion write-down.

U.S. index futures rose and the dollar advanced against the Euro after Citigroup announced the results, fueling investor optimism that the credit-market contraction may be easing.

“I think the worst is largely behind us,” Malcolm Polley, who manages $1 billion as president of Stewart Capital Advisors LLC in Indiana, Pa., said in a press release.

The bank’s write-downs and credit losses from the collapse of the subprime mortgage market now total almost $40 billion, more than Zurich-based UBS AG and Merrill Lynch.

Revenues fell 48 percent to $13.2 billion, compared with the average estimate of $11.1 billion by analysts surveyed by Bloomberg. Results included $7.6 billion of write-downs and credit costs on mortgages and bonds, $1.5 billion on leveraged buyout loans and $1.5 billion on auction-rate securities. The bank wrote down the value of assets it absorbed last year from so-called structured investment vehicles by $212 million. The company also marked down the value of bond insurance contracts by $1.5 billion. Citigroup set aside about $1.8 billion to increase reserves for bad consumer loans.

The bank’s Tier 1 capital ratio — a financial measure monitored by regulators that gauges a bank’s ability to withstand loan losses — rose to 7.7 at the end of the quarter from 7.1 percent at the end of 2007. The minimum for a “wellcapitalized” rating from U.S. regulators is 6 percent. Citigroup sets its own target at 7.5 percent, partly to ensure its AA- rating from Standard & Poor’s.