(Reuters) — Bayer AG shares jumped on Thursday after it revealed plans aimed at resolving multibillion dollar lawsuits linked to glyphosate, a move welcomed by activist shareholder Elliott Associates, which has taken a sizable stake in the chemicals company.

Shares in the German group, which have lost more than a fifth of their value since March, were up 8% Thursday morning, their highest value in seven weeks.

Bayer said on Wednesday it had hired an external lawyer to advise its supervisory board and has set up a committee to help to resolve the glyphosate litigation issue.

Marks Manns, a fund manager at Union Investment, one of Bayer's largest German shareholders, said the share price was likely bolstered by anticipation of an earlier settlement.

"Investors want more certainty as quickly as possible. But it is for management to weigh up a quick settlement against how many billions you could save by holding out. I don't want a settlement at all costs," he said, adding that Bayer's negotiation position was for now highly unfavorable.

The company's shares have been under pressure following its $63 billion acquisition of Monsanto, which brought with it massive legal issues after more than 13,400 plaintiffs alleged the company's glyphosate weedkiller caused cancer - a claim Bayer contests.

Deka Investment, another major German shareholder said taking more legal expertise on board was "the right step," and was mainly a token of acknowledgement by the supervisory board of shareholder criticism.

Elliott on Wednesday welcomed Bayer's steps, as it revealed for the first time its holding in Bayer shares worth 1.1 billion euros ($1.25 billion).

In a statement, Elliott also said Bayer's recent moves helped to resolve uncertainty linked to the glyphosate issue and lead to settlements with limited financial costs.

"Elliott believes that Bayer's discounted share price today does not reflect the significant underlying value of its constituent businesses, or the potential value realization opportunity that is in excess of 30 billion euros," it said.

Major shareholders have criticized Bayer for its handling of the glyphosate issue that resulted in a vote of disapproval of its top management at April's annual general meeting.