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Byline: Mark L. Sirower and Steve Lipin

The recent spate of merger activity has rekindled the animal spirits of the deal community, but the stock market reaction to some deals shows that investors aren't taking mergers-and-acquisitions "stories" hook, line and sinker as they did in the 1990s. With M&A activity on the rise, acquirers face tough questions from Wall Street and other constituencies about the strategic and financial merits of a combination. And that means acquirers need a carefully thought-out communications plan.

To some, M&A communications is an afterthought. This is a mistake. Well-conceived M&A communications during due diligence can help the prospective acquirer think through whether the transaction is a good idea in the first place, and whether it will give investors more reasons to buy than to sell.

Also, investors performing their own due diligence use the information contained in press releases, investor presentations, conference calls and interviews. And employees, customers and …