When investors try to determine which U.S. companies face worrisome pension obligations, they ought to search beyond manufacturers with bulging retiree rolls.

Although old-line manufacturers from automakers to chemical producers are certainly among the companies that bear watching for pension problems, companies as diverse as newspaper and television broadcaster E.W. Scripps (SSP) and boat and bowling equipment maker Brunswick Corp. (BC) could be potential risks, too, according to analysts.

That's because such companies carry a high level of pension obligations relative to their size. Although different methodologies are used -- some analysts compare obligations to the market capitalization of a company, others compare it to the book value of the business -- the theory is the same: Pension size doesn't matter as much as the heft of the company carrying it.

"When pension issues emerge, investors tend to flock to the usual suspects, like the auto industry or companies with a large absolute amount of pension assets," says Michael A. Moran, a strategist in Goldman Sachs Group Inc.'s (GS) global markets institute. "But looking at the size of a plan relative to the size of a company is very important. Materiality needs to be a part of the analysis."

Sharp market declines and falling interest rates have combined to batter traditional defined benefit pension funds. This may lead some companies to make hefty contributions to their pension plans this year, which could hurt earnings and discourage investors.

Goldman and Credit Suisse Group (CS) have come up with remarkably similar lists of companies that could suffer in 2009 from pension shortfalls generated in the rough markets in 2008. The rosters don't confer a definitive scarlet letter on those included because the analysts' models generalize their calculations to apply to a wide universe of companies, when in reality each corporation uses different actuarial and accounting assumptions that could result in better outcomes.

But because most companies follow a Dec. 31 fiscal year, and won't issue annual reports revealing 2008 pension data for at least another few weeks, the analysts' models are the closest thing investors have for an initial screening tool to begin sifting for trouble.

By Moran's reckoning, the companies with the highest pension obligations relative to their sizes include not only automakers like General Motors Corp. (GM) and Ford Motor Co. (F), but also technology consulting firm Unisys Corp. (UIS); office supplies retailer OfficeMax Inc. (OMX); E.W. Scripps and Brunswick; telecom company Qwest Communications International Inc. (Q); and food packaging company Pactiv Corp. (PTV), among others.

Credit Suisse's David Zion's research has similarly picked out GM, Ford, Unisys, Brunswick, Scripps and OfficeMax.

With the exception of Qwest and Unisys, companies mentioned by the two analysts didn't immediately return phone calls. Qwest declined to comment, saying it would update investors on its pension obligations during its year-end earnings release on Feb 10; Unisys said it is still determining its pension expense and obligations and will also update investors on its status on a Feb. 10 earnings call.

Actuaries at consulting firms agree that the biggest question that comes into play when trying to sniff out potential pension minefields is the size of the plan relative to the sponsoring company. But while there could be problem companies lurking off the beaten path, they say the bulk of the firms encountering pension headwinds are going to be in the expected places.

"Where you look are at industries that have been around a long time, that have had very large labor forces at one time, but the companies may be smaller now than they once were. That means manufacturing, chemicals, and other similar old-line industries," says Michael Archer, chief actuary at Towers Perrin, who declined to name any specific companies at risk. "Their pension plans didn't get smaller, so the companies still have those obligations at the same time that their revenues have declined."

-By Lynn Cowan, Dow Jones Newswires; 301-270-0323; lynn.cowan@dowjones.com

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