NEW YORK (CNN/Money) - According to a new study from Dresdner Kleinwort Benson's portfolio management group, many of the past year's worst performing stocks could be in for more pain before the month runs out.

Justin Lahart, senior writer at CNN/Money, talks about a new study that takes a closer look at which sectors may face selling pressure as the end of October approaches. Play video (Real or Windows Media)

For many of nation's mutual funds, Oct. 31 marks the end of the tax year and managers are more likely than ever to offset their capital gains by selling losers. The reason? In a rule that went into effect last year, the Security and Exchange Commission now requires that funds report their after-tax performance. And this year, unlike last year, most funds are sitting on fat gains.

But which stocks, exactly, are most likely to be get sold? If a fund manager bought, say, Coca-Cola Enterprises at the beginning of the year he'd be sitting on a loss, and have an impetus to sell. But if he bought it three months ago, he'd have a gain.

The thing to do, the Dresdner strategists reckoned, is to look at trading volume and prices over the past year and determine what the typical tax basis for stocks was and then figure out which stocks are trading 5 percent or more below that basis. Coca-Cola Enterprises, it turns out, isn't one of them. Its competitor, Pepsi Bottling Group, is. And so are 62 other companies in the S&P 500.

On a sector basis, the telecommunications group -- chock full of losing stocks like AT&T, Qwest and Verizon, -- looks most likely to come under tax-selling pressure. Next up are energy and healthcare.

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The Dresdner strategy group figures that the best way for investors to capture the tax-selling effect may be through exchange traded sector funds, like the SPDRs that trade on the Amex. The Health Care, Energy and Materials SPDRs (there isn't one for telecom) will likely come under pressure though the end of the month -- a shorting opportunity -- and then should recover once the pressure abates.