US pharma major Pfizer reportedly held talks for takeover of AstraZeneca at a record valuation for the British rival, which would also have been the largest-ever deal in the sector.

Britain's Sunday Times, citing senior investment bankers and industry sources, reported that Pfizer had proposed a £60bn ($100bn, €73bn) acquisition of AstraZeneca.

There had been informal talks about the deal between the companies, but, no negotiations were under way after AstraZeneca spurned the move, according to the newspaper. The deal would also have been the largest ever takeover of a British firm by a foreign company.

Nevertheless, Pfizer, which is famous for its anti-impotence drug Viagra, could come back with a fresh approach, said The Sunday Times.

Pfizer is known for a number of mega mergers in the pharma sector. It was involved in three of the 10 deals worth more than $30bn in the last two decades, according to Bloomberg data. The reported deal with AstraZeneca would top Pfizer's 2000 purchase of Warner-Lambert Co for $87bn.

Spokesmen of both companies declined to comment on the report.

AstraZeneca is the country's tenth-largest company and the second-biggest pharma company after GlaxoSmithKline with 50,000 employees globally. It has been a takeover target of many pharma giants, as it is facing expiry of patents on a number of best-selling drugs.

Despite the troubles, its experimental cancer drug under development has attracted attention across the globe.

AstraZeneca currently has a market valuation of about $80bn, while Pfizer is valued at $193bn.

The British company reported a 6% fall in earnings in the fourth quarter of 2013, and it noted a continued decline in profits due to competition from generic drug makers.

AstraZeneca is due to announce its first quarter results on 24 April.