NEW YORK — Standard&Poor’s announced several changes to the S&P 500, S&P MidCap 400 and S&P SmallCap 600 indices on Tuesday, which take effect after the close of trading on March 3.

¶ S&P noted that changes to the indices do not reflect any opinion on the investment merits of the companies. However, changes do often affect stock ownership, since many investment portfolios are linked to the S&P indices.

¶ Austin, Minn.-based food producer Hormel Foods Corp. will replace alternative asset manager American Capital Ltd. in the S&P 500, and Ventas Inc., a Chicago-based health care real estate investment trust, will replace clothing maker Jones Apparel Group Inc.

¶ As of Tuesday’s close of trading, American Capital and Jones Apparel had market capitalizations of $306 million and $267 million respectively, ranking them 499th and 500th in the index.

¶ Financial services company Trustmark Corp. will replace Hormel in the S&P MidCap 400. Hormel shares closed up 39 cents at $31.95, but jumped $1, or 3 percent, to $32.95 in after-hours trading after the announcement. Ventas shares climbed $1.42, or nearly 6 percent, to $25.69 in aftermarket electronic trading.

¶ Lennox International Inc., a supplier of heating, ventilation and air conditioning products, will replace homebuilder Hovnanian Enterprises Inc. in the S&P MidCap 400, as information technology services provider Stanley Inc. moves up to replace Lennox in the S&P SmallCap 600.

¶ AECOM Technology Corp., a provider of professional technical and management support services, will replace mortgage insurer PMI Group Inc. in the S&P MidCap 400.

¶ Hovnanian and PMI Group have market capitalizations of $74 million and $64 million, respectively, well below the $750 million minimum market cap needed to be admitted to the S&P MidCap 400 index.

¶ In the S&P SmallCap 600, Computer Programs and Systems Inc., a health care information technology company, will replace microchip component maker Axcelis Technologies Inc. Also, Web data analysis company comScore Inc. will replace regional bank operator Anchor BanCorp Wisconsin Inc.

¶ Axcelis and Anchor BanCorp have market caps of $22 million and $19 million respectively, below the $200 million minimum needed to be admitted to the index.