Dennis Gillings, the co-founder of Quintiles, and other investors in the world’s largest life science services company, are looking to cash in on Quntiles’ IPO from last year. According to an SEC filing made early Monday, they are offering some 17.5 million shares worth $939.3 million.

Gillings could earn some $200 million should the offering be successful.

Quintiles (NYSE: Q), which is based in Durham, went public in May of last year for nearly $1 billion in what is believed to be the largest initial public offering of stock by a Triangle-based company.

Shares offered in the IPO were priced at $40. Quntiles has sold has high as $55 over the ensuing 10 months.

Now investors including Gillings are looking to reduce their holdings.

Gillings, who is the largest individual shareholder of the company with some 19 percent of outstanding shares, along with Bain Capital and TPG Funds lead the shareholders looking to move shares at a price of $54.46, the filing says.

Quintiles shares closed Friday at $54.11.

In a statement, Phil Bridges, director of corporate communications for Quintiles, noted that Quintiles’ “private equity sponsors” were looking to “diversify their positions.”

He made no mention of Gillings,

“The secondary S-1 filing indicates Quintiles’ private equity sponsors’ intention to offer common stock to the public. This offering would enable our private equity sponsors to diversify their positions,” Bridges said in response to an inquiry from WRALTechWire.

“Quintiles itself is not offering any stock. As such, the company would not receive any funds from the offering.

“With this filing, Quintiles has entered into a traditional “quiet” period as required by the Securities and Exchange Commission so it is inappropriate for me to comment further.”

As Bridges noted, the company said in the filing it will not receive any proceeds from the offering.

Gillings is looking to sell some 4 million shares as are Bain and TPG, which are the company’s largest institutional holders.

If the offering sells, Gillings’ holdings would be reduced  to 20.475 million or 15.6 percent of available shares.

Bain’s holdings would be reduced to 15 percent, and TPG funds would end up with a 13 percent stake.

Underwriters of the offering have the option of purchasing 2.25 million shares.

Firms involved in the offering include Morgan Stanley, Barclays, J.P. Morgan, Citigroup, Goldman, Sachs & Co., Wells Fargo Securities, BofA Merrill Lynch, Deutsche Bank Securities, Baird, William Blair, Jefferies, Guggenheim Securities, Piper Jaffray, Raymond James, RBC Capital Markets and UBS Investment Bank.

The filing can be read online.