Sylvamo (SLVM) shares rose past 6% in recent trading Tuesday, a day after the company said its board of directors unanimously approved a one-year shareholder rights plan, effective immediately.

The decision followed the resignation of two Atlas-affiliated directors, which ended a 2023 cooperation agreement between the two companies, Sylvamo said.

Atlas currently holds an economic interest of about 21.5% of Sylvamo's shares, including 16% direct ownership and 5.5% through derivatives, according to the statement. After Nov. 13, Atlas will no longer be bound by standstill restrictions under the cooperation agreement, Sylvamo said.

The rights plan, which will expire Nov. 9, 2026, is meant to prevent any investor or group from gaining control of Sylvamo without fairly compensating shareholders or allowing the board enough time to evaluate options, the company said.

Price: 45.67, Change: +2.82, Percent Change: +6.58