SandRidge Energy Inc (SD.N), under fire from shareholders about company performance, said on Monday its board of directors adopted a shareholder rights plan that would make it more difficult to take control of the U.S. oil and gas company.
The plan would "guard against tactics to gain control of SandRidge without paying all stockholders a premium for that control," SandRidge said in a statement.
A representative for SandRidge was not immediately available to comment on whether the board took action in response to a specific attempt to gain control of the company.
The rights plan is triggered if a person or group acquires 10 percent or more of SandRidge's common stock. The threshold rises to 15 percent in the case of certain institutional investors, the company said.
Last week, a second large investor called for SandRidge to replace Chief Executive Officer Tom Ward and overhaul its board, saying the oil and gas company has suffered from "critical failures of management and board oversight."
Mount Kellett Capital Management, which owns 4.5 percent of SandRidge, joined hedge fund TPG-Axon urging change at the Oklahoma City, Oklahoma, company.
TPG-Axon, which controls a 6.2 percent stake in the company, has called for SandRidge to consider selling itself, for Ward to step down, and for changes to the board, saying management's strategy has been "incoherent, unpredictable and volatile.
Shares of SandRidge fell 1 percent to $5.56 in after-hours trading, adding to a 5 percent fall to $5.62 in regular New York Stock Exchange trade.
(Reporting By Anna Driver; Editing by Bernard Orr and Tim Dobbyn)