U.S. District Judge Martin Feldman's disclosure report, which covers investments for 2009, shows he owned eight energy-related investments including stock in Exxon Mobil Corp.
However, in an attachment to the report, the judge said he sold his Exxon Mobil stock this June when he was hearing the oil spill case.
In last year's disclosure report, Feldman owned up to 16 energy-related investments.
Among the assets sold was stock in Transocean, the Switzerland-based company that owned the drilling rig operated by BP that is now spewing oil into the Gulf of Mexico.
Feldman, a 1983 nominee of President Reagan, struck down the Obama administration's six-month moratorium on deepwater oil drilling in the Gulf of Mexico, disputing what he said was the government assumption that because one rig exploded, others posed an imminent danger.
On Thursday, Feldman refused to place his ruling on hold while the government appeals.
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Feldman's Exxon Mobil stock in 2009 was valued at $15,000 or less and produced an income of less than $1,000.
The judge has an investment in Ocean Energy valued between $15,001 and $50,000, which produces interest valued between $1,001 and $2,500.
Other holdings include investments in Provident Energy Trust, El Paso Corp., Energy Transfer Equity, Basic Energy Services, Valero Energy Corp. and Crosstex Energy LP.
Values of investments and income are expressed in ranges rather than precise amounts.
An Associated Press analysis has found that more than half of the federal judges in districts where the bulk of Gulf oil spill-related lawsuits are pending have financial connections to the oil and gas industry. This could complicate the task of finding judges without conflicts to hear the cases.
Federal judicial rules require judges to disqualify themselves from hearing cases involving a company in which they have a direct financial interest.
However, financial conflict rules have some leeway. For example, a judge does not have to step aside if investments are part of a mutual fund over which they have no management control.
Further, mere ties to companies or entities in the same industry, no matter how extensive, do not require disqualification.