Feb 20 (Reuters) - HP Inc said on Thursday it would implement a poison pill plan lasting a year, as Xerox Holdings Corp pushes ahead with its efforts to acquire the PC maker.

Xerox recently raised its offer earlier this month by $2 to $24 per share, following several rejections of its previous buyout offers by the PC maker. HP shares closed up 0.9% at $22.64 on Thursday and was flat after hours.

The implementation of the stockholder rights plan aims to stop investors from amassing more than a 20% stake in the company.

"The rights will not prevent a combination of HP with another business, but should encourage Xerox (or anyone else seeking to acquire the Company) to negotiate with the Board prior to attempting to impose some combination that is not in the best interests of the HP shareholders," HP said in its statement.

Xerox did not immediately respond to a Reuters request for comment. (Reporting by Neha Malara in Bengaluru: Editing by Krishna Chandra Eluri)