Rosetta Stone Inc shares rose nearly 44 percent in their trading debut Thursday, following the company's initial public offering, the fourth in the United States this year.

Rosetta Stone, a provider of language instruction products, opened trading at $25, the morning after it priced its IPO at $18, exceeding the estimate range.

In morning trading, Rosetta Stone shares were changing hands at $25.69 on the New York Stock Exchange.

Rosetta Stone sold 6.25 million shares, netting proceeds of $112.5 million in its initial public offering on Wednesday.

People are starved for companies that have good internal growth, and positive cash flow so they can fund themselves even before an IPO, said Francis Gaskins, president of research firm IPO Desktop.

The strong demand for the stock and its jump suggest Rosetta Stone and its underwriters, Morgan Stanley and William Blair & Co, could have priced the deal more aggressively.

They didn't mind leaving money on table, because this IPO increases consumers' awareness of Rosetta Stone, which helps top-line revenue growth, Gaskins added.

Rosetta Stone, which provides language instruction services to individuals, companies and schools primarily through CD-ROMs, has attracted attention through an advertising campaign that has featured U.S. Olympic swimming gold medal swimmer Michael Phelps.

(Reporting by Phil Wahba, editing by Matthew Lewis)