A cut in a company’s dividend or its elimination is not the death knell for a stock, but it’s often a step in that direction.

So if you’re a stockholder in such well-known corporations as Bristol-Myers Squibb, General Motors, or ConAgra Foods, you might want to get out while the getting is good.

The reason: The dividend payouts of all three companies are in jeopardy, which invariably denotes internal problems, a frequent forerunner of lower stock prices.

That SOS about dividend risks is being flashed by Morningstar, the Chicago-based research firm and mutual fund industry tracker. In a just-issued report, Morningstar analysts zero in on 19 companies with above-average dividends whose payouts are in peril and whose stocks the analysts feel should be shunned.

Morningstar began hoisting dividend warning flags in January 2005 and since then has uncovered eight companies whose payouts were subsequently cut or eliminated, including Marsh & McLennan, Equity Office Properties, and Delphi.

An equities strategist at Morningstar, Josh Peters, notes that any one of a host of reasons could place a dividend in jeopardy, such as liquidity crises, major lawsuits, including asbestos claims and patent challenges, and unfavorable regulatory changes.

Other warning signs include a lot of debt, a payout ratio above 80%, and when a company ‘s stock sports the highest yield in its industry. Yet another red flag: when an established string of dividend increases comes to a halt.

The Morningstar analysts who studied the three companies mentioned above made the following observations:

• General Motors: The 50% dividend cut GM announced in February does little to suggest the remaining annual $1 payout rate is safe. The company’s challenges continue to mount, and the stock remains a highrisk investment. Fixed costs and substantial long-term retiree obligations make it highly vulnerable to even minor performance variations. There is no reason to think that GM’s market share won’t continue to drop, putting additional stress on the profitability of its auto operations.

• Bristol-Myers Squibb: The company is engaged in four patent challenges related to its anti-platelet drug Plavix. It was the company’s top-selling drug through the third quarter of 2004 and has patent protection until 2011 unless its patent is found to be invalid. If Bristol and its development partner, Sanofi-Aventis, do lose patent protection on Plavix, Bristol’s largest American product, the dividend could be in serious jeopardy and Morningstar would drop its fair value estimate for the stock by $4 a share.

• ConAgra Foods: In Morningstar’s opinion, ConAgra has been doling out cash to its shareholders at an unsustainable rate, considering the declining fundamentals of its packaged food business and the elimination of about 40% of its sales base over the past couple of years. Few of the company’s brands generate enough consumer demand or hold strong enough market positions to provide the leverage necessary to charge higher prices at retail. ConAgra has done a poor job of investing in internal opportunities like brand building and product innovation. As with Campbell Soup and Heinz, both of which cut their dividends significantly in recent years, the only way ConAgra can free up the capital necessary to invest in its brands is to reduce its payout to shareholders.

Rounding out Morningstar’s list of 19 companies with dividend problems are FairPoint Communications, Sara Lee, Peoples Energy, Precision Drilling Trust, Primewest Energy Trust, Xerium Technologies, Consolidated Communications, Duquesne Light Holdings, New Century Financial, Annaly Mortgage Management, Lance, Tasty Baking, Alaska Communications, Citizens Communications, Newcastle Investment, and San Juan Basin Royalty.

Interestingly, the highest dividend-paying company on the list, with a recent annual payout of 17.4% is New Century Financial, a subprime mortgage lender whose stock, reflecting housing woes and bankruptcy speculation, has collapsed to less than $2 from around $52 last May.

To Mr. Peters, the message is clear: If you’re going to own a stock for its dividend, that dividend had better be secure. All too often, he says, conservative investors fall victim to high yield.: