AstraZeneca, the leading British drugmaker, refused an acquisition offer by U.S. pharmaceuticals group Pfizer for a second time, it was reported Monday.

Pfizer confirmed that it previously submitted a preliminary, non-binding indication of interest to AstraZeneca in January 2014 regarding a possible merger transaction. But AstraZeneca spurned the offer.

The proposal contained a combination of cash and shares in the combined entity which represented an indicative value of 46.61 pounds (76.62 U.S. dollars) per AstraZeneca share.

According to recent market developments, Pfizer contacted the British company on Saturday seeking to renew discussions in order to develop a proposal that could be recommended by both companies to their shareholders. However, AstraZeneca again declined to engage with the offer.

"If the transaction is consummated, AstraZeneca shareholders would become significant shareholders in the combined company and participate in significant value creation opportunities, including benefiting from the potential growth opportunities," Pfizer said in a statement.

However, reports said that the deal would rekindle fears over the loss of industrial expertise and investment in the British life sciences sector.

Shares in AstraZeneca jumped as much as 17 percent on Monday morning. It set a new 52-week high during Monday's trading session when it reached 4,796.5 GBX. Over this period, the share price is up 39.97 percent.

AstraZeneca is at the heart of Britain's life sciences sector, which has a market value of 51.5 billion pounds.

The company supports 30,000 jobs, including 7,000 staff directly. Its exports were almost 7 billion pounds representing about 2.33 percent of total British export of goods. (1 pound = 1.68 U.S. dollars)