It’s only common sense: With the economy widely expected to slow later this year – ditto profit growth – it pays to fatten your portfolio with shares of the fastest-growing companies, which have the wherewithal to buck any economic slowdown.

I’m writing about this idea, not that it’s anything earth-shattering, in response to an e-mailed note from a reader, Seymour Abend, who wrote: “Dan, you must be getting ancient or feeble minded to write the dribble you did in today’s column. Your readers care about companies with growing earnings, not slowing earnings. Come on. Get with it.”

Mr. Abend took issue with a secondary item in Monday’s column in which I mentioned that a well regarded newsletter, Dow Theory Forecasts of Hammond, Ind., had alerted its subscribers to a number of companies it expects to experience slowing per-share earnings growth this year, among them Merrill Lynch, Johnson & Johnson, MetLife, and Nike.

In my mind, that’s meaningful information. But seeing as our unhappy reader wants to focus solely on the positive, let’s look at the names the newsletter’s editor, Richard Moroney, expects to produce above-average earnings growth this year. Specifically, there are four companies he thinks can outstrip the 11% earnings gain projected in 2006 for the S&P 500 by Standard & Poors’s chief economist, David Wyss.

Mr. Moroney sees the following four achieving 2006 earnings growth of between 13% and 18% versus last year, and offering prospective 12-month stock gains of 15% to 20%.

Biomet ($35.37), a maker of surgical and nonsurgical medical devices. This year’s per-share earnings growth is pegged at 13%.The company is enjoying strong sales of reconstructive devices, particularly knees and dental implants. An impressive pipeline of devices should drive future growth; in December, the Food & Drug Administration approved Biomet’s ceramic-on-ceramic hip, which should boost market share.

Demographic trends also favor the company. As the population ages, the need for orthopedic implants will rise. With life expectancy increasing, more orthopedic patients are outliving their implants and requiring new ones. Likewise, today’s longer-lasting, less-invasive devices appeal to younger patients, and such products should widen the pool of potential recipients.

L-3 Communications Holdings ($84.15),a maker of specialized systems for satellite, avionics, and marine communications. Earnings growth of 18% (more than 50% better than the gain estimated for the S &P 500) is projected this year. That includes the $2.65 billion acquisition of government intelligence and communications specialist Titan Corporation This purchase made L-3 the ninth-largest Pentagon contractor, with $4.7 billion worth of defense contracts last year.

The backlog of funded orders at the end of 2005 reached $7 billion, up 47% from the end of 2004. For the year, cash flow surged 44%, to $798 million. Management has already forecast 2006 revenue growth of at least 27%, on expectations of robust military spending on communications, intelligence, and security. L-3 is also poised to benefit as communications becomes more important to warfare and as the military increasingly outsources training and intelligence services.

UnitedHealth Group ($56.17), one of the country’s largest health-benefits providers. Profit growth is pegged at 17% this year, followed by 16% growth in 2007. In part because of the efficiencies inherent in its large size, United-Health has been successful at keeping premium increases at or above medical cost growth, which has resulted in improved profitability.

Expansion through acquisitions is the name of its game. In December, the company acquired PacifiCare Health Systems for $9.2 billion, which gave it a greater presence in the Medicare and small-group markets and more exposure in western states, including California. Since Medicare’s new prescription-drug program took effect in January, United-Health has signed up 4.3 million members. Further, it expects to enroll as many as 6 million members in Medicare programs by the end of the year.

Walgreen ($45.45), the nation’s largest drug store chain. Earnings growth of 13% is seen this year. Prescription sales, which represent 64% of total sales, should benefit from the new Medicare prescription-drug program and the increase in generic versions of drugs losing patent protection over the next two years. Generic drugs sell at lower prices but generate higher profit margins.

In recent quarters, Walgreen has experienced strong sales of general merchandise, and it plans to offer more competitive pricing in the hopes that customers will purchase more items per transaction. To boost its appeal to a broad range of shoppers, Walgreen is putting more emphasis on convenience. About 84% of its stores are free-standing locations and 31% are open 24 hours a day.

dandordan@aol.com