Investor Carl Icahn has increased his stake in St. Paul-based Lawson Software, Inc., according to a regulatory document filed Tuesday.

Icahn, who held about 13.8 million shares of the company in May, now owns about 16.9 million shares-increasing his stake in the company from about 8.5 percent to roughly 10 percent.

When Icahn purchased stock in the business software company earlier this year, he did so “in the belief that the shares were undervalued,” according to a regulatory filing. The filing also indicated that Icahn wanted to have conversations with Lawson “to discuss the business and operations of [Lawson] and the maximization of shareholder value.”

Lawson spokesman Terry Blake said in a Wednesday phone interview that Lawson's leaders have met with “Icahn's team,” and he described the discussion as “cordial and constructive.” He said that the company does not disclose the specific details of such meetings with major shareholders.

Blake also said that Icahn had purchased additional shares since May. Icahn owned roughly 9.6 percent of the company's shares at the end of August, he said.

Icahn is the chairman of New York-based Icahn Enterprises, L.P., a diversified holding company engaged in many different business segments. According to a report by Reuters, Icahn is a billionaire who is currently attempting to take over Santa Monica, California-based Lions Gate Entertainment Corporation, and he is also pushing for a seat on the board at Cambridge, Massachusetts-based Genzyme Corporation, a biotechnology company.

Forbes magazine in March ranked Icahn at the 59th spot on its list of billionaires, stating that the investor has a net worth of $10.5 billion. The magazine refers to Icahn as America's richest “shareholder activist,” and it says that he resides in New York.

On Tuesday, Lawson's stock closed at $8.48-up 28 cents, or about 3.4 percent. Shares were trading down about 0.6 percent to $8.43 during Wednesday morning trading.

Lawson is among Minnesota's 50 largest public companies based on revenue, which totaled $736.4 million in its most recently completed fiscal year.