NEW YORK, April 15 (Reuters) - Rosetta Stone Inc (RST.N: Quote, Profile, Research) shares priced at $18 in the company's initial public offering, above the estimated $15 to $17 price range, a source with direct knowledge of the deal said Wednesday.

Rosetta Stone sold 6.25 million shares, raising about $112.5 million.

The IPO's lead underwriters, led by Morgan Stanley (MS.N: Quote, Profile, Research) and William Blair & Co, have the right to purchase up to an additional 937,500 shares of common stock to cover over allotments.

Rosetta Stone has been approved to list on the New York Stock Exchange under the symbol "RST."

(Reporting by Phil Wahba)