NEW YORK ( TheStreet) -- Pfizer ( PFE) may have led some investors to the exits on Thursday when the giant pharmaceutical company made official the divestiture plans for its animal health and nutrition businesses.

Shares reacted negatively to news that everyone on Wall Street had already taken for granted: It's considering strategic alternatives for its animal health and nutrition businesses, that could include a spinoff or asset sale.

Pfizer shares closed 3% lower on heavy volume Thursday, with more than 85 million shares traded. The three-month average daily share volume for Pfizer is 44 million shares. Pfizer shares dropped sharply at the open and drifted down through the day.

A potential spinoff could be a payday for investors. It could also ultimately provide Pfizer with the cash to buy back shares and invest in a potential blockbuster drug. However, analysts say the potential payday for divestitures was already reflected in the 16% rise in Pfizer shares year to date.

In effect, it's back to the basics of the pharmaceutical business and the stock fundamentals, with Pfizer saying in print what's already been assumed by Wall Street.

"People haven't owned this stock for the R&D prowess it hasn't exhibited, but because they might be beneficiaries of spinoffs," said Les Funtleyder, health care analyst at Miller Tabak and manager of the Miller Tabak Healthcare Transformation Fund.

In this respect, Thursday's Pfizer trade was a classic sell-on-the-news-that's already-known event. However, there's a more negative way to read the Pfizer announcement, too.

For proof of the strategic alternatives being the "worst kept secret" on the Street, just look back at the last quarterly earnings conference call with analysts. The first question for new Pfizer CEO Ian Read, from Goldman Sachs analyst Jami Rubin, included these requests: "Share with us, if you have narrowed your options regarding strategic alternatives for your diversified businesses ... clarify what your plans will be if assuming you do spend or sell some of these businesses, what you will do with the cash proceeds?"

In answering the analyst question, Pfizer CEO Read said, "We are still reviewing all of our alternatives on the businesses outside of the core. We expect to start making some announcements during the second half."

The Miller Tabak manager said he read that comment from Pfizer's CEO as a statement that some divestitures would be completed by year-end. However, what Pfizer said on Thursday, right at the start of the "second-half of the year" period that it outlined for announcements, is that it will begin a 12-month to 24-month process of pursuing strategic alternatives for animal health and nutrition. Other Street analysts and investors contended that the naming of the units to be divested showed Pfizer's intentions to be less than "transformational" in nature.

Taking the shorter-term view, "I was under the distinct impression, and Pfizer may have felt otherwise, that they would execute at the end of year," Funtleyder said. The Miller Tabak manager did not go as far as to express disappointment in Thursday's announcement and the 12-month to 24-month timeline for decisions, but said it also would indicate to some investors that there is little upside left in shares after the 16% run this year.

Pfizer's CEO did say during the last conference call, "I don't see it as a big bang. I don't foresee at some point second half suddenly coming out with a detailed master plan, but certainly, we'll lay out decisions we've taken and decisions we haven't ... to give a clearer path forward."

Yet since it has been known that the company is looking to sell, an investor would have had reason to believe that Pfizer already had some informal conversations with potential buyers.

"Everyone knew that they were interested in doing this, so if a company was even remotely interested and aware, they would probably would have reached out to Pfizer if they didn't reach out to you," Funtleyder said. Importantly, he said that while Pfizer never mentioned the animal health and nutrition businesses by name in its spinoff discussions, "a good portion of Wall Street has done so." The narrowing of divestiture candidates only confirmed what was already expected, rather than being a major news development.

Any investor who owned Pfizer for the spinoff potential could read the official announcement as indication of a delay in the plans, or in the least, perceive a risk in the timeline to completion of the divestitures. Investors sizing up the 16% return in Pfizer S&P 500 return of 7% could be taking money off the table, while it wouldn't necessarily change the outlook for a long-term investor (the Miller Tabak fund owns Pfizer shares).

"Ultimately, I think they get these transactions done, but it might take a long time, longer than some investors are willing to wait for," Funtleyder said.

-- Written by Eric Rosenbaum from New York.

>To contact the writer of this article, click here: Eric Rosenbaum.

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