Henry Schein Inc., Long Island's largest company by revenue, will join the S&P 500 after the close of trading Tuesday, replacing health technology company CareFusion Corp., which is being acquired by Becton, Dickinson and Co.

Melville-based Henry Schein joins LI companies Pall Corp., Kimco Realty Corp. and  Cablevision Systems Corp., owner of Newsday, in the index of large capitalization stocks. The S&P 500 is widely followed as a measure of U.S. stock market performance.

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Previously, Schein, a global distributor of dental, veterinary and health care products with a market capitalization of $11.7 billion, had been a constituent of the S&P MidCap 400, an index of midsized companies.

"We are honored that Henry Schein will be added to the iconic S&P 500," said Schein chairman and chief executive Stanley M. Bergman.

When companies enter or leave an index, portfolio managers who follow that index often buy or sell shares of that company.

In Monday morning trading, shares of Henry Schein climbed 2.5 percent to $139.83.

CORRECTION: Earlier versions of this story were incorrect about how many Long Island companies are in the S&P 500.