Efforts by private equity firms to sell stakes in portfolio companies through initial public offerings continued late this week as two North American companies took steps toward coming to market.

Talecris Biotherapeutics Holdings Corp, controlled by private equity firm Cerberus Capital Management LP , on Friday set terms for its planned $849.3 million IPO, signaling it was likely to price it within weeks. The company is based in North Carolina.

Dollarama Inc, backed by private equity firm Bain Capital, filed late on Thursday for an initial public offering on the Toronto Stock Exchange. The retailer is based in Montreal, Canada.

A source close to the Dollarama deal said the IPO would raise some C$300 million ($278 million) and that underwriters hoped to close the offering by mid-October.

The prospective deals are the latest in a string of private equity backed IPO filings in North America, as buyout firms look to take advantage of improved markets to exit investments.

U.S. retailer Dollar General Corp, backed by private equity firm Kohlberg Kravis Roberts & Co , said in August it was looking to raise up to $750 million in an IPO.

Other deals in the pipeline include a prospective $1.15 billion IPO by independent oil exploration company Cobalt International Energy Inc, whose owners include Riverstone Holdings LLC and The Carlyle Group .

A number of recent IPOs in the United States were by companies owned by private equity firms, such as chipmaker Avago Technologies Ltd , owned in part by KKR, that raised $745.2 million in August, and Emdeon Inc , which makes and licenses health records management systems and is partly owned by General Atlantic Partners.

Talecris, which produces plasma-derived protein therapies, said in the filing it would use the IPO proceeds to pay down debt.

Talecris estimated it would sell 44.7 million shares for between $18 and $20 per share, according to a prospectus filed with the U.S. Securities and Exchange Commission. It plans to list on Nasdaq under the symbol TLCR.

Talecris was formed in 2005 when German drug and chemicals group Bayer sold its blood products unit to Cerberus and Ampersand for about $590 million.

About 35 percent of shares being sold are held by existing shareholders, and the company said in the filing that it expects net proceeds from the IPO to be $514.8 million.

The Talecris IPO lead underwriters are Morgan Stanley, Goldman Sachs & Co, Citi and J.P.Morgan.

While the Talecris prospectus did not specify a date for pricing, a company typically comes to market within two or three weeks of setting terms of its IPO.

Dollarama is 80 percent controlled by Boston-based Bain Capital, which bought its stake in a leveraged buyout deal in 2004. Bain provided about C$364 million of equity for the C$1.05 billion deal, according to media reports at the time.

Dollarama, which sells products for C$2 or less, is the largest operator of dollar stores in Canada.

Dollarama said in its filing that it planned to use about C$70 million of the IPO's proceeds to repay some promissory notes, C$38 million to repay in full the term loan, and the majority of the remainder to pay down other notes.

$1=1.078 Canadian Dollar

(Reporting by Phil Wahba)