It may be years before the wisdom of the deal to create

AOL Time Warner

is proved out. In the meantime, it looks as if many of the growth-oriented investors in

America Online

(AOL)

aren't waiting around to watch the rest of the story.

AOL-Time Warner merger: Join the discussion on our

message boards. In the two days since the

deal with

Time Warner

(TWX)

was announced, AOL stock has fallen 12%, as a growing number of people on the Street have asserted that though the deal gives AOL unmatchable assets and a promising future, it will likely slow the revenue growth at a company that's been consistently building sales more than 50% year after year.

On a standalone basis, AOL's revenue would probably grow a minimum of 25% annually over the next two or three years, and probably in the 32%-to-35% range, estimates Michael Tucker, senior investment analyst at mutual fund company

Federated Investors

, an AOL shareholder. But lumping the company together with Time Warner, Tucker estimates the resulting company's revenue will grow in the 13%-to-16% range. "That's a dramatic difference from where AOL was last week," he says. The slower revenue growth "is a concern to me," he adds. "I think it's a concern to a lot of people."

'Dead Money'?

Similar calculations published the morning after the landmark AOL-Time Warner announcement put a damper on AOL's stock like a bad headache the morning after a wild party. Citing AOL's likely transformation into a company that has revenue growth of about 15% and earnings before interest, taxes, depreciation and amortization of 20%,

Warburg Dillon Read

analyst Michael Wallace called the stock "dead money in the near term as investors grapple with this issue." Wallace, whose firm doesn't do underwriting for AOL, has a strong buy rating on the stock.

Christopher Lord, general partner of

Pivotal Asset Management

, cites a likely drop in AOL's cash-flow growth, to 20% from 50%, as one of the factors behind AOL's stock-market swoon Tuesday. "The numbers are the numbers," he says. His firm doesn't own AOL stock.

But not everyone is as pessimistic about growth.

The Other Side of the Coin

Jeffrey Diecidue, portfolio manager at private investment firm

Unicom Capital

, says he expects the Internet side of the organization will be able to put the music, print and moving-image content from the traditional-media side to good use. "It's clearly a growth stock," he says. "You're going to monetize those assets to the high-growth medium of the Internet. ... Instead of Time Warner dragging down the growth rate, AOL will accelerate the growth rate at Time Warner." He adds, "I could argue that you could get this thing growing at 40% on an EBITDA basis," he says. Unicom holds shares in both AOL and Time Warner.

Jordan Rohan, media analyst at

Wit Capital

, is also bullish on the deal, but for slightly different reasons. He says the market should be given more credit for its ability to value the disparate assets of AOL Time Warner using a variety of multiples. In such an analysis, he says, the heady growth of AOL's advertising and e-commerce business would justify a larger revenue multiple than, say, a more mature business such as publishing. "I think investors would be making a mistake to analyze AOL Time Warner as one large company," he says. "It's more instructive to dig deeper into the value of each particular business." Rohan, whose firm hasn't done underwriting for AOL or Time Warner, has a buy rating, his firm's highest, on AOL, with a 12-month price target of 105.

That's not to say that people unsure of AOL Time Warner's growth prospects don't see eventual promise in the stock. "The combined company is going to be an awesome Internet/media company," says Federated's Tucker. "It's going to raise the bar for all of AOL's competitors." In fact, at Tuesday's closing price of 64, Tucker said AOL's price was attractive. "But," he adds, "you just have to be willing to hold on to it longer."