Sequa Corp.'s takeover of Atlantic Research Corp. of Alexandria this week is a bitter lesson for ARC's founders but instructive, nevertheless, for other rapidly growing public companies around the Beltway. If they want the continuity and independence that ARC lost, then speedy adoption of antitakeover measures may be their only option.

ARC joins a long list of public companies that have paid the ultimate price for being consistently profitable and innovative and for establishing significant market positions in their respective industries. The founders and managers of those companies dared to believe that by producing quality products and holding down costs, and by significantly boosting sales, earnings and dividends, they would keep stockholders happy and continue running their companies. That's the ideal envisioned by entrepreneurs, many of them founders of companies like ARC.

But idealism is in short supply in corporate boardrooms and executive suites from which hostile takeover bids are launched. For shareholders who tender their stock in hostile takeovers, idealism means getting a handsome return on their investments, and justifiably so. A shareholder's loyalty to management is only as strong as the company's performance and stock price.

Former ARC chairman Coleman Raphael noted in a recent interview with Post staff writer Michael Isikoff that his company consistently managed to produce a greater than 20 percent annual return on shareholder equity. That was both a blessing and a curse, as it turned out. ARC's performance ultimately made it a target for raiders. Indeed, Clabir Corp. of Connecticut launched a takeover bid for ARC last year. Clabir drew blood in the unexpected strike and the sharks soon began circling ARC.

Washington's Ferris & Co. sketched the sequel to Clabir's hostile bid in a prophetic report last January.

"We think {Clabir} will back off and sell its shares {in ARC}," Eliot H. Benson, a vice president and director of research at Ferris, wrote in the company's monthly review of regional stocks. "In view of these recent developments," Benson continued, "we would not be surprised to see another company step forward and make an offer for {ARC}. We consider it an attractive property, one with significant market positions in military and commercial areas, along with strong cash flow and an impressive earnings record."

Indeed, Clabir did back off when Sequa emerged as a white knight to block an unwanted takeover at ARC. But ARC was in play by then, as arbitrageurs began accumulating the company's stock.

In the February 1987 issue of Ferris' Regional Review, Benson wrote: "Hold {ARC's} stock and buy if it declines to 30. We consider the stock attractive on the fundamentals and believe that {ARC} may attract another suitor or white knight."

Sequa, as it turned out, reversed roles and launched a hostile takeover offer for ARC, capitalizing on holdings gained in its purchase of ARC stock from Clabir.

Small wonder, then, that Raphael, in the Post interview last week, lashed out at "vulture" speculators who create turmoil for management and employes.

Raphael's bitterness over the takeover of ARC is understandable. But his opinion that hostile takeovers are "bad for the country" shouldn't be dismissed as mere sour grapes from an executive who lost a takeover battle. The case is yet to be made that hostile takeovers create new wealth, help generate new businesses, improve productivity, increase employment or strengthen America's competitive position.

Hostile takeovers are applauded in the investment community because they benefit stockholders. They're also advocated as a cure for inefficient management. But that's often a smokescreen for less idealistic motives. It's highly debatable that these organized raids lead to greater management efficiency, as perpetrators and their supporters would have people believe.

In some instances, in fact, disruption, displacement and destruction often are the legacy of hostile takeovers. A few examples close to home make the point.

Allied Stores Corp. bought the venerable Washington-based Garfinckel, Brooks Brothers, Miller & Rhoads Inc. in a hostile takeover six years ago and in turn was taken over by Campeau Corp. of Canada. The Garfinckel chain has been split up as a result, putting people out of work and significantly altering competition in some retail markets.

Washington's Haft family surprised Safeway Stores Inc. last year with a hostile takeover attempt, forcing the giant supermarket chain into an expensive defensive posture. The Hafts eventually backed off, but Safeway now has to close stores and sell off assets in a major restructuring of the company.

In Lynchburg last year, the former management of Craddock-Terry Shoe Corp. finally yielded in the face of a hostile takeover bid by a group of investors with no experience in shoe manufacturing. The new owners were forced only a few months ago to close the company's five plants, putting hundreds of people out of work.

There might be fewer Craddock-Terrys and ARCs if more companies followed the examples of Giant Food Inc. or Hechinger Co. Nonvoting stock in the hands of the public effectively rules out the possibility of a hostile takeover at either company. Stockholders' willingness to own nonvoting stock in those companies is a powerful vote of confidence in management's proven ability to operate highly successful enterprises.