The low-ball bid for Immunex

American Home Products Corp. isn't talking about its surprise bid to acquire the rest of Immunex Corp., so outsiders can only speculate about the pharmaceutical company's motives. Given the size of the offer and its timing, it's hard to escape the conclusion that the unsolicited bid is a hostile one.

The bid was delivered in a letter the night before a previously scheduled board meeting. AHP is offering $14.50 a share, for a total of $263 million to IMNX shareholders...