Medpace (NSDQ:MEDP) yesterday said affiliates of Cinven Capital Management are launching a secondary offering of 4 million shares of its common stock at $31.50 per share, for gross proceeds of $126 million – not including an underwriter’s option worth another $18.9 million.

The offering includes a 30-day underwriters option to purchase an additional 600,000 shares, Cincinnati-based Medpace said. The contract research organization won’t see any of the proceeds from the sale, and instead pledged to buy back some 2 million shares, leaving the remaining 2 million available to public buyers.

The offering is slated to close Dec. 5. Jefferies and Credit Suisse Securities are joint bookrunners for the offering, Medpace said.

Last August, Medpace raised more than $185 million in its initial public offering, including an underwriter’s over-allotment that added more than $24 million to the IPO.