Although the Gulf of Mexico oil spill is having the most impact on companies in the energy sector, the accident may also lead to a collateral impact on a number of other publicly traded companies exposed in some way to the Gulf region.

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The companies in the energy sector directly impacted by the Gulf of Mexico oil spill are well known to investors. They include BP (NYSE: BP) as the well operator and Transocean (NYSE: RIG) as the rig owner. Anadarko Petroleum (NYSE: APC) has a non-operated working interest in the well being drilled, and Halliburton (NYSE: HAL) provided oil services on the rig during the drilling of the well.

Gulf Coast Banks

A number of banks have made filings or given commentary during conference calls spelling out a possible impact from the accident. Although most of these are boilerplate warnings required by legal counsel, they still bear mention.

MidSouth Bancorp (NYSE: MSL) warned of a potential impact when the company filed its SEC Form 10-Q for the first quarter of 2010. The company said the accident "could impact the company and our earnings" but that it could not "reasonably determine" the extent at the present time.

MidSouth Bancorp is headquartered in Lafayette, La., and had $576 million in total loans as of March 31, with the majority in Louisiana and Texas.

Hancock Holding Co. (Nasdaq: HBHC), a large regional bank headquartered in Gulfport, Miss., made a similar warning in its 10-Q filing for the quarter, as did Hibernia Homestead Bancorp (OTCBB:HIBE), a small community bank in Louisiana.

The Real Danger

The danger for all banks with substantial operations in the Gulf region is a delay or temporary shutdown in offshore drilling, which would spill over into layoffs by companies dependent on this business.

Omega Protein Corp. (NYSE: OME) is a large producer of omega-3 fish oil, and it owns several facilities and operates fishing fleets in the Gulf of Mexico. The company has been forced to relocate its fishing fleet due to closures by the Louisiana Department of Fisheries and Wildlife of certain fishing grounds in the Gulf of Mexico.

Omega has so far not seen a material adverse effect on its fishing catch, and it also has fishing facilities on the Atlantic coast to cope with any shortages.

Guilt By Association

Many companies have suffered from guilt by association and haven't seen any impact yet. Boyd Gaming (NYSE: BYD) has four casinos in Louisiana and Mississippi. During the company's Q1 2010 earnings conference call, management said it hadn't seen any drop in business yet due to the oil spill.

Cost increases for restaurants are also a worry for investors, who peppered some management teams with questions on recent conference calls. Ruth's Hospitality Group (Nasdaq: RUTH) sources some of its shrimp from the Gulf of Mexico, but it reported no cost increases or shortages. The company also noted that it had other non-Gulf suppliers and that prices were locked in for 2010.

Spill Is Far Reaching

The next wave of publicly traded companies suffering a secondary impact from the spill are less known by investors. They include mostly companies outside the energy sector, but with operations in the Gulf Coast region. (While many companies are suffering due to the spill, some are actually prospering. To learn more see Companies Affected By The Oil Spill.)

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