By Elias Schisgall

The chief executive officer of Seer has offered to buy the company for $2.45 a share in cash, plus two contingent value rights, the biotechnology company said.

Seer on Thursday said that CEO Omid Farokhzad, who also serves as the company's chair, had made an unsolicited proposal to buy the company.

It said its board would establish a special committee of independent directors to evaluate the proposal and other alternatives.

Shares of Seer surged 31%, to $2.13, in after-hours trading. The stock closed down 0.6%, at $1.62, and has slipped 11% this year.

The offer comes as a pair of minority shareholders, Bradley Radoff and Michael Torok, are also bidding to take the firm private. The company rejected their third offer, at $2.40 a share in cash with one contingent value right, in May.

Radoff and Torok have launched a proxy battle in response to the company's repeated rejections.

Write to Elias Schisgall at elias.schisgall@wsj.com