NEW YORK -- Most investors think of initial public offerings as chances to buy the stock of young, hot and often obscure companies for the first time.

But the IPOs that have been announced in the past few weeks include some familiar names, including Toys R Us and the firm that created the Nielsen television ratings.

One reason for these deja vu IPOs is that the private equity firms that bought many well-known companies, and took them private during the past decade, are now trying to cash out.

That's happening in part because of legislation that would raise the income tax rate on private equity firms. If the firms sell now, they will keep more of the profit than if they wait and sell next year.

Although selling shares in these companies now may make good sense for their owners, buying these shares may make less sense for inves- tors.

So far this year, initial offerings by private equity funds have fallen 4.4 percent in their first month of trading, based on data through May 25, according to the IPO-tracking firm Renaissance Capital.

That's far worse than the average performance this year for all IPOs, which have gained 0.5 percent during their first month.

Investors have been hesitant to embrace IPOs from private equity groups in part because they're often saddled with debt.

As the examples show, the most recent private equity-backed deals are much bigger than those without private equity involvement, and some carry fairly heavy debt loads.

Still, the name-brand companies may carry some appeal.

Francis Gaskins of said well-known IPOs often attract retail investors, who personally can identify with the companies.

"It's not just a stock symbol on the board," he said.

Recently announced IPOs:

1. Nielsen Holdings (NH)

Consumer ratings and research company (backed by private-equity groups)

Size of IPO: Up to $1.75 billion

Company outlook: Nielsen faces tough competition from rivals such as comScore, and it's saddled with a whopping $8.6 billion in debt.

2. Toys R Us (TOYS)

Toy retailer (backed by private-equity groups)

Size of IPO: $800 million

Company outlook: The toy industry is improving, and Toys R Us has been taking market share away from competitors such as Target and WalMart.

3. The Fresh Market (TFM)

Gourmet grocery chain

Size of IPO: $345 million

Company outlook: The retailer operates 95 stores in the Southeast, Midwest and Mid-Atlantic regions. But it could have up to 500 stores in the U.S. in the future.

4. Zipcar (ZIP)

Car-sharing service

Size of IPO: $75 million

Company outlook: Zipcar has never posted a profit. Don't expect that to change anytime soon. The company warned potential investors that it may be difficult to make money.