NEW YORK (Bloomberg) - Teekay Corp., the world's largest oil-tanker owner, fell the most in almost a month after reporting a fourth-quarter adjusted loss as shipping rates tumbled.

Teekay reported an adjusted loss of $33.3 million, or 45 cents a share, matching the average of 12 analyst forecasts compiled by Bloomberg. Revenue fell 35 percent to $517.8 million, the Hamilton, Bermuda-based company said on Friday.

Teekay dropped $1.06, or 4.2 percent, to $24.03 on the New York Stock Exchange, the biggest decline since February 5.

"The tanker market was fairly weak in the fourth quarter, which translated into a pretty tough quarter for the company," said Greg Lewis, a New York-based analyst at Credit Suisse who has an "outperform" rating on the stock.

Including a $109.9 million gain from interest-rate swaps, the company reported net income of $15.9 million, or 22 cents a share.

Teekay diversified its revenue sources by entering into liquefied-natural-gas transportation and the offshore shuttle- tanker market. About half of revenue comes from oil tankers, for which rates in the quarter slumped by almost half from the previous year.

The Baltic Dirty Tanker Index, a measure of spot rates for crude-oil shipments, averaged 646 during the fourth quarter, down from 1,246 a year ago. The index has rebounded to average 1,021 this year after reaching 1,216 on January 15, the highest level in more than a year.

Teekay reported a loss of $650.9 million, or $8.98, a year earlier.

Excluding losses from interest-rate swaps and goodwill impairment related to the company's acquisition of Teekay Petrojarl ASA, an owner of floating production storage and offloading, or FPSO, in the North Sea, it reported a year- earlier adjusted net income of $53.2 million, or 73 cents a share.