Lawson Software has received an unsolicited $1.8 billion buyout offer from privately held Infor, which is owned by Golden Gate Capital.

The cash offer is equal to $11.25 per share of Lawson common stock.

Shares of St. Paul-based Lawson have been rising on speculation of an acquisition and are up about 20 percent recently. Shares closed Friday at $11.55.

"The parties are engaged in discussions regarding this proposal; however, there can be no assurance that any agreement will be reached," Lawson said Saturday in a statement.

Lawson has retained Barclays Capital to evaluate the Infor offer. The Lawson board has yet to decide whether to try to sell the company or make any other major changes in strategy.

In the event it rejects the offer, Lawson said: "The board believes that the company is well-positioned to continue executing its strategic plan" to grow organically.

Lawson, founded in northeast Minneapolis in the 1970s, makes financial and HR software for midsize businesses and school districts. It has been a so-so financial performer since it went public at about $16 per share nearly a decade ago. In recent years it has seen management changes and mergers, reorganizations and layoffs.

New York activist investor Carl Icahn, who often takes stakes in struggling or undervalued companies in hopes of a third-party buyout, has amassed an 11 percent stake in recent months. He is Lawson's single largest shareholder.

Scott Berg, an analyst at Feltl & Co. in Minneapolis, has estimated that a "deal could get done in the $14 to $16 range."

News of the Infor offer could trigger bids from Hewlett-Packard, IBM, Microsoft, Oracle or SAP, analysts speculate.

Golden Gate Capital, based in San Francisco, has $9 billion under management. In addition to software maker Infor, its investments include Romano's Macaroni Grill and Herbalife.

Neal St. Anthony • 612-673-7144