Two Maine paper companies that were acquired by separate private equity firms are now headed for public ownership.

Papers detailing the initial public offerings were filed Monday with the Securities and Exchange Commission for Verso Paper Group and NewPage Group Inc. Verso has mills in Jay and Bucksport; NewPage in Rumford. Combined, the mills employ about 3,000 Mainers.

“It’s very interesting that they are happening at the same time,” said Lloyd Irland, a Winthrop-based paper industry consultant. “But it’s not that surprising; that’s the way private equity firms work. It’s very natural that an IPO comes along at some point.”

Verso, which is owned by Apollo Management, is seeking to raise $300 million from the sale of 18,750,000 shares of common stock. NewPage, owned by Cerberus Capital Management, is hoping for $805 million also through the sale of stock, but it does not list the number of shares, nor the expected price at offering.

The Verso group, which includes mills in Michigan and Minnesota, will still be controlled by Apollo, which intends to retain 67 percent of the common stock, according to the filing. The initial public offering price is expected to fall between $16 and $18 per share.

Cerberus is expected to retain a significant amount of NewPage shares, but the exact percentage isn’t spelled out in the filing.

“We plan to use the proceeds to further reduce debt and return cash to our principal stockholders,” said Amber Garwood, spokeswoman for NewPage. NewPage had nearly $3 billion in debt at the end of 2007.

According to the SEC filing, Verso intends to use the cash generated by the IPO to pay off about $288 million in debt and to expand production, invest in R&D and consider acquisitions.

Improving conditions within the coated paper markets is one possible reason for the IPOs. According to the preliminary prospectus for Verso, several North American mills have closed their coated paper machines, constricting supply while world demand for the glossy paper continues to rise.

Verso’s prospectus states the average price per ton of its coated paper sold in the second quarter of 2007 at $797. Six months later the average price rose to $840 per ton. As a result, the company is expecting $86 million in additional revenue for 2008 from its coated paper products.

NewPage’s average coated paper prices rose from $797 per ton in 2004 to $900 per ton in 2007.

Overall industry prices are expected to continue rising from an average of $888 per ton for No. 5 coated paper – an industry benchmark – in the second quarter of 2007 to $1,100 per ton by the fourth quarter of 2008.

Irland said often a private equity firm will invest to a certain point in an acquisition to improve its balance sheet, but then looks for an opportunity to generate cash. If the market for coated paper is good, it could just be a good time to sell, he said.

The NewPage Group includes 12 paper mills, located throughout the U.S. and Nova Scotia. It acquired Stora Enso North America in December, doubling its production capacity. From the sale, Stora Enso received approximately $1.5 billion in cash, a $200 million note, and a 19.9 percent equity interest in the company.

For 2007, NewPage reported net sales of $4.7 billion, with an income loss of $95 million. Verso reported 2007 net sales of $1.628 billion, with net income loss of $111 million.

If Verso’s IPO flies, it will be traded on the New York Stock Exchange under the symbol VRS. NewPage would also be listed on the NYSE, traded under the ticker NWP.