British asset manager Schroders, which holds a 2% stake in AstraZeneca, said it is disappointed by the UK drugmaker's decision to reject the takeover offer from US rival Pfizer, and called on the company to enter into talks again.

"Schroders notes with disappointment the quick rejection by the AstraZeneca board of the latest offer from Pfizer and the decision of the Pfizer board to draw a premature end to these negotiations by calling their latest proposal final," said Sue Noffke, manager of Schroders Prime UK equity fund.

"As long-term shareholders, we are strong believers in AstraZeneca and the potential for its innovative growth pipeline, however, given the increase in the offer we would encourage the AstraZeneca management to recommence their engagement with Pfizer, and subsequently their shareholders."

Schroders is AstraZeneca's 12th biggest shareholder.

Earlier, other shareholders in AstraZeneca including AXA Investments and Jupiter Fund Management openly criticised AstraZeneca's management for its tough stance against Pfizer.

On 19 May, AstraZeneca rejected Pfizer's final takeover offer, saying the improved bid still undervalues the company. The final bid valuing AstraZeneca at about £69bn ($116bn, €85bn) or £55.00 per share "undervalues the company and its attractive prospects," AstraZeneca said in a statement.

"Even assuming that other key aspects of any proposal had been satisfactory, that the price at which the board of AstraZeneca would be prepared to provide a recommendation would have to be more than 10% above the level contained in Pfizer's Friday Proposal," Leif Johansson, chairman of AstraZeneca, said.

"The Final Proposal is a minor improvement which continues to fall short of the board's view of value and has been rejected."

Pfizer earlier increased its offer for AstraZeneca to £55 per share from £53.50 per share, adding that it cannot raise the offer further. This is the fourth proposal Pfizer has made.

The US company added that it will not make a hostile offer directly to AstraZeneca shareholders and will only announce a firm intention to make an offer with the recommendation of the board of directors of AstraZeneca.