LONDON (Reuters) - EBay Inc may be hungry to jettison its ill-fitting acquisition of Skype and refocus on its core markets and payment businesses. But selling off in an initial public offering the Web communications company that now boasts more than 400 million members worldwide may not be the best outcome for existing shareholders.

Why not offer up Skype to eBay shareholders and give them a choice of whether to sell or keep the independent company?

The spin-off technique is used all the time by companies in other sectors but not in high-tech. Silicon Valley sees this as heresy, apparently still believing that the splash a successfully-managed IPO can make in the market will prove more lucrative.

It's a legacy from the heady days of the 1990s IPO craze that many technology companies and their bankers believe they still know best how to time the sale of fast-growing companies to maximize their value. EBay says it wants to hold an IPO for Skype in the first half of 2010, betting that the near death of the IPO market in recent years will create a yearning for new issues that rocket fuels its own stock offering.

But the tech sector's love of making a big IPO splash has a dark side.

If eBay's management presses ahead with an offering, it would probably have to sell a substantial stake in Skype off to the stock market at a price that valued the company at less than the estimated $1.7 billion at which the investment is carried in its books. It would do this in the hope that, down the road, Skype's share price would go up, allowing eBay to sell off the rest of the company at higher prices, thus dodging the need for further embarrassing writedowns. EBay has already written off $1.4 billion of the estimated $3.1 billion purchase price.

But this might not be the best outcome for eBay investors, largely because it would force them to sell part of their holding in Skype at what might be a disadvantageous time. A demerger would at least preserve optionality, allowing investors to decide whether they wanted to hang on to their Skype shares or to dispose of them, depending on their individual circumstances and appetites.

Another big advantage of a spin-off over a partial IPO for eBay is that it would allow the group to exit cleanly and renew its focus on its core business. This is something that its major shareholders have clamored for its management to do for years.

After the misguided acquisition strategy that used mergers like Skype to disguise the fading growth in eBay's core auctions business, the company's beleaguered shareholders deserve better. EBay shares have been a value trap, stuck in a range between $10 and $15 for the last five years or so. The stock has been on the mend over the past year as new management has demonstrated a revived interest in creating shareholder value. Merger and disposal activity by eBay in recent weeks offers hope that eBay will concentrate on auctions once again. Spinning off Skype to eBay shareholders could be the next positive step.

(Editing by David Evans) -- Eric Auchard is a Reuters columnist. The opinions expressed are his own --