Victoria's Secret said it has adopted a shareholder-rights plan, better known as a poison pill, to fend off a potential hostile bid as activist investor BBRC International maneuvers to buy up shares.

Victoria's Secret shares gained 3.2% in premarket trading.

The maker of women's loungewear and sleepwear said Tuesday that the plan, which expires in one year, was adopted in response to BBRC raising its position in Victoria's Secret in recent months to about 13% of outstanding shares.

According to the company, BBRC has been violating antitrust laws with its stock purchases for nearly three years by failing to file required forms and observe regulatory waiting periods. The firm has now made corrective filings that would allow it to acquire up to 49.99% of all Victoria's Secret voting stock at the end of a waiting period set to expire at midnight on May 22, the company said.

Victoria's Secret is responding with a plan that will let shareholders buy stock at a 50% discount should any one investor accumulate 15% or more of the company's outstanding float, or 20% if the investor is considered passive.

"The board determined it was necessary to adopt a rights plan to protect the long-term interests of all Victoria's Secret shareholders and guard against tactics to gain control of the company without paying all shareholders an appropriate premium for that control," Chair Donna James said.

Victoria's Secret has engaged in open and constructive talks with BBRC founder Brett Blundy and other firm representatives over the past three years and values Bundy's input, James said.