The launch of the second version of the iPad should help Apple Inc's shares, but don't expect a repeat of the surge that came after the first version was released last year.

New products have fueled the bellwether's relentless upward momentum, making it one of the most valuable companies in the world, but next-generation products have traditionally resulted in milder gains.

Apple is hosting a media event on March 2 to unveil the new iPad tablet computer, which is expected to be thinner, faster and have a new front-facing camera that will enable video chatting through the company's FaceTime application. For details, see

A new version is more of an additive where an entirely new category is a game-changer, said Jerome Heppelmann, chief investment officer at Old Mutual Focused Fund in Berwyn, Pennsylvania, who owns shares. It isn't that there will be limited upside after the release, it will just be limited compared to a new category.

When Apple released the iPad in 2010 the stock surged 10.6 percent in the first month after it hit shelves, continuing a trend of double-digit percentage gains in the first month after a new line of products is introduced.

Subsequent product versions resulted in less robust gains in the first month after release. After next-generation versions of the iPhone were released, the stock posted either milder gains or dips.

The biggest product-related gain was after the iPhone was introduced in 2007. Shares gained 41.1 percent between that day and when it was officially launched because it was viewed as revolutionary.

The iPad sequel is not expected to make such a splash.

There tends to be a 'sell the news' reaction after this kind of event, said Michael Quigley, a technology analyst at Wedgewood Partners in St. Louis. But as we get estimates on demand, it usually ends up being much more optimistic than people were betting. We're expecting it to rally.

Shares of Apple were lately down $2.61, or 0.8 percent, to $350.60. The stock is up 8.7 percent in 2011 and has gained 314 percent in the last five years.

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