According to a report from the Sunday Times, U.S. pharmaceutical company Pfizer has expressed interest in taking over Anglo-Swedish giant AstraZeneca for a total of $101 billion. Although both companies declined to comment on the matter, the British newspaper quoted senior industry sources who confirmed that informal discussions over a possible deal had taken place. AstraZeneca apparently turned down the offer, Reuters reported.

Despite being the second-largest pharmaceutical group in the UK, AstraZeneca's future growth is quite uncertain. The group is facing patent expiries on several of its most profitable drugs. Moreover, new drug development has not been particularly successful over the past couple of years for the company. For these reasons, reports of rivals approaching it for a takeover are not rare. The group has previously been linked with proposals from Swiss giant Novartis and the largest British pharmaceutical group, GlaxoSmithKline.

In a bid to secure its future AstraZeneca has been concentrating on the development of its experimental cancer drugs, which may be what attracted Pfizer. In fact, the U.S. pharmaceutical giant has also been struggling with patent expiries, most notably Lipitor — a product used for treatment of high cholesterol. The two companies have cooperated on a series of projects, including the new clinical trial for cancer drugs, so they are familiar with each other's portfolios, Reuters said.