Lear Corp.'s board approved a plan to reduce future tax liability and restrict ownership changes at the auto-parts supplier.

The plan preserves the value of certain tax assets linked to net operating loss carryforwards that allow companies to apply current operating losses to future years' profit to reduce tax liability, Lear said Tuesday.

The board acted to limit shareholders' purchases because Lear's ability to use the carryforwards would be restricted based on certain ownership changes, the Southfield, Mich., company said.

The plan would dilute voting power for shareholders who increase their stakes more than 4.9 percent of outstanding shares. For shareholders who already own more than 4.9 percent of the shares, the trigger that would dilute voting power if they increase their stakes in the company by half of 1 percent or more.

The plan is scheduled to expire in December 2018.

Other companies have recently adopted similar shareholder-rights plans. Homebuilder Ryland Group Inc. said Tuesday its board approved a plan aimed at reducing future tax liability and restricting future ownership changes of the company.

In connection with its shareholder plan, Lear declared a dividend of one preferred share purchase right for each outstanding common share, payable to holders of record as of Jan. 2.