The Carlyle Group filed on Tuesday for an initial public offering of its common units as it looks to join rivals Blackstone and KKR as listed private equity firms, but the filing comes amid deep uncertainty on global equity markets.

The U.S. IPO market has struggled as concerns about Europe's debt crisis and a weak recovery in the United States have made markets volatile. A number of deals were withdrawn last month.
"If Carlyle files in this timeframe, in basically a market meltdown, something doesn't seem right," said Scott Sweet, senior managing partner at IPO Boutique.

Given the market conditions and the poor performance of other listed private equity players like Blackstone Group and Apollo Global Management, and the complex listing of Kohlberg Kravis Roberts & Co may also dampen investor appetite.

"There is going to be pricing pressure for this deal, given the weak demand for financial IPOs and the performance of the listed companies," said Josef Schuster, founder of Chicago-based IPO research and investment house IPOX Schuster.

Shares in Blackstone, currently valued at $14.6 billion, have dropped by a third since a near 3-year high in late-April.

The Carlyle filing with the U.S. Securities and Exchange Commission lists an offering size of $100 million, though that is typically a placeholder. Sources said in June the offering could be as large as $1 billion.

Carlyle was valued at $20 billion in September 2007, before the credit crisis sent stock markets sliding.

The buyout firm said it generated economic net income -- a measure of profitability used by private equity firms -- of over $1 billion last year and around $770 million in the first half of this year.

Blackstone's second-quarter economic net income was $703 million.

SPECK OF SAND

Carlyle will be managed by its general partner Carlyle Group Management LLC, which intends to make quarterly dividend payments to common unit holders.

Carlyle is controlled by its senior managers and investors which own minority interests in the business - Mubadala Development Co, an Abu-Dhabi based strategic development and investment company, and California Public Employees' Retirement System (CalPERS).

Private equity companies and hedge funds typically give little, if any, power to shareholders in decision making.

"Investors have to be very comfortable with the fact that they are just a speck of sand on the beach when it comes to having any say in what's going on with the company," said David Menlow, President of IPOfinacial.com.

Carlyle, founded in 1987 by David Rubenstein, Daniel D'Aniello and William Conway, said it currently manages about $153 billion in assets -- versus $159 billion at Blackstone.

The buyout firm told the U.S. Securities and Exchange Commission in a preliminary prospectus that J.P. Morgan, Citigroup and Credit Suisse are underwriting the IPO.

Carlyle has invested in companies including Dunkin Brands, Alliance Boots and Freescale Semiconductor.

The filing did not reveal how many units the company planned to sell or their expected price.