(Sharecast News) - Shares in healthcare company PureTech fell on Tuesday as the company said it and US-based Nektar Therapeutics had ended merger talks only four days after they announced a potential tie up.

"These discussions were early in nature and the required announcement created the impression that discussions were more advanced than they were," PureTech said on Tuesday, referring to disclosure requirements under UK takeover rules after media speculation.

"Given the early stage of the discussions and the potential for an extended period of uncertainty, these discussions were terminated."

Shares in the company fell 17% at one stage but had recovered in afternoon trade to be 5.5% lower at 216p.

Technically the PureTech is still under offer, and Nektar said it reserved the right to make or take part in an offer within the next six months, with the agreement of PureTech's board, if circumstances "materially change" or a third party announces a firm intention to make an offer for PureTech.

Reporting by Frank Prenesti for Sharecast.com