United Natural Foods Joining S&P MidCap 400 Index

NEW YORK (AP) — United Natural Foods Inc. will replace Amerigroup Corp. in the S&P MidCap 400 Index after the close of trading Friday, Standard & Poor's said Monday.

Health insurer Wellpoint Inc. is acquiring its smaller rival Amerigroup in a $4.46 billion deal expected to close shortly.

Ixia, which supplies communications equipment, will replace United Natural Foods in the SmallCap 600 index.

Standard & Poor's also said Abiomed Inc., which makes medical devices, will replace Cascade Corp. in the SmallCap 600 index. Toyota Industries Corp. is acquiring Cascade in a pending transaction worth about $759 million.