Hospital chain HCA Inc. plans to raise $4.6 billion in its third initial public offering of common stock, more than three years after it was taken private in a leveraged buyout by a group of private equity investors.

The Nashville, Tenn. company's plans were made public Friday as four IPOs were postponed after the Dow Jones industrial average dropped nearly 1,000 points Thursday and investors grew increasingly worried that the growing European debt crisis could have daunting repercussions for U.S. corporations that do business in Europe.

IPOs of dental office services provider Smile Brands Group Inc., metals processor Ryerson Holding Corp. and real estate investment trust Madison Square Capital Inc. were all delayed Friday, with no expected trading date. Chinese oil company MIE Holdings Corp. has not been officially delayed, but won't begin trading this week.

HCA didn't set a price for the shares or say how many it plans to sell. But it said in a Securities and Exchange Commission filing that it expects gross proceeds of about $2.5 billion, not including any extra shares it may sell to its underwriters to cover excess demand. It will use the funds to pare $26.86 billion in debt and for general corporate purposes.

HCA operates 162 hospitals and 106 surgery centers in 20 states and the United Kingdom. In its SEC filing it said it provides up to 5 percent of all U.S. hospital services as the largest, nongovernment hospital operator in the United States, and it has a "substantial market presence" in 14 of the 25 fastest growing U.S. markets.

"We believe we are well positioned in a number of large and growing markets that will allow us the opportunity to generate long-term, attractive growth through the expansion of our presence in these markets," the company said in the filing.

But HCA also said its "substantial debt" could limit its growth strategy.

HCA said its first-quarter net income climbed 8 percent to $388 million, from $360 million, a year earlier. Revenue rose 1.5 percent to $7.54 billion.

HCA also said its charity care and uninsured discounts jumped 43 percent to $1.58 billion in the quarter.

The company first went public in 1969 with 11 hospitals. It completed a $5.1 billion leveraged buyout in 1988 and then re-emerged as a public company in 1992.

In 2006, a group of investors including Bain Capital, Kohlberg Kravis Roberts and Merrill Lynch Global Private Equity, took the company private again in a $21 billion leveraged buyout. That came as HCA struggled with sliding earnings and escalating expenses for the uninsured.

But HCA's chairman and CEO at the time, Jack Bovender, said then that the company already was considering going public again in five years or more.

BofA Merrill Lynch, Citi and J.P. Morgan are leading a large group of underwriters for the latest offering. The list includes Barclays Capital, Credit Suisse, Deutsche Bank Securities, Goldman Sachs & Co., Morgan Stanley, and Wells Fargo.

HCA plans to list its stock on the New York Stock Exchange under the ticker symbol "HCA."