After being the subject of buyout and takeover rumors in 2011 for as much as $1 billion, life science services firm PRA International may be going a different route now in order to raise money.

The Raleigh-based contract research organization has filed a “confidential submission” of a possible stock sale through an Initial Public Offering with the SEC.

PRA chose not to disclose either the total amount of money it is seeking or how many shares would be offered at what price range.

The company is owned by Genstar, which first acquired PRA in 201, took it public in 2004, and reacquired majority ownership in 2007.

If PRA were to go public, it would be following the path of Quintiles (NYSE: Q), the world’s largest life science services firm, which raised more than $1 billion for itself, shareholders and investors.

In 2011, talk about PRA circulated at the same time Wilmington-based PPD, also a CRO, went private.

In a short announcement, PRA said proceeds from an IPO would be used “to reduce outstanding borrowings under its credit facilities, provide liquidity for existing shareholders, pay certain fees and expenses, and for working capital and general corporate purposes.”

PRA recently acquired Clinstar, a San Francisco-based CRO that specializes in conducting clinical trials in Eastern Europe, particularly Russia. Clinstar also had a business development office in Durham. All of those employees were absorbed by PRA.

Formerly known as PRA Holdings, the company launched in 1976 and has some 5,000 employees worldwide. PRA moved to Raleigh from Virginia in 2008.