(Sharecast News) - US tobacco giant Philip Morris International bought a 22.6% stake in London-listed inhaler-maker Vectura, as health experts warned investors not to approve a takeover.
Vectura announced last week that its directors were planning to unanimously recommend a takeover by PMI at 165p a share.

PMI said on Wednesday that it has purchased just over 135.5m shares in Vectura at the offer price of 165p and was looking to make further market purchases at the same price.

Vectura shareholders have until 15 September to decide whether to sell their shares to Philip Morris.

The news came as a group of health experts, doctors and charities urged Vectura shareholders to reject the PMI takeover.

Signatories of an open letter written directly to shareholders, led by Asthma UK and the British Lung Foundation, argued that accepting PMI's money would "significantly hamper Vectura's ability to continue operating as a viable, research-oriented business".

The signatories asked Vectura shareholders "to consider both the business risks and the moral conflict of the proposed takeover" and said tobacco companies should not profit from treating the illnesses their products cause.

Should the deal fall through, US private equity firm Carlyle has a 155p a share offer on the table.