Market whispers had put the two companies together in a concerted campaign that had seen the pharmaceutical group's shares gyrate wildly in recent weeks. Yesterday's unequivocal denial of talks, which analysts believed could have led to a pounds 15bn bid by the giant Swiss group, saw Zeneca's shares fall 23p to 1,097p.
David Barnes, chief executive refused to comment further on bid talks as he announced a 44 per cent jump in pre-tax profits for the six months to June to pounds 506m. Despite the good figures, the market also worried about comments from Mr Barnes suggesting a slowdown in profits growth in the second half thanks to the cost of promoting new drugs.
He said: "We continue to face highly competitive markets in all our businesses. The group faces the exciting and demanding challenge of launching an unusually large number of new products. I am confident the returns from this near- term revenue investment programme will help secure Zeneca's future growth."
The big improvement in profits partly reflected a pounds 100m charge in the previous year's figures to fund a restructuring of Zeneca's speciality and agrochemicals businesses. Underlying profits were 12 per cent better after a 6 per cent rise in sales from pounds 2.38bn to pounds 2.53bn.
That included pharmaceuticals sales, which exceeded pounds 1bn for the first time in a six-month period as a 7 per cent volume increase was offset by a 1 per cent decline in prices as cuts, especially in Italy, continued to squeeze the industry.
Zeneca's older drugs, such as Tenormin, fell but the shortfall was more than made up by newer treatments. Sales of Diprivan, an anaesthetic, and cancer drug Zoladex grew at 21 per cent and 33 per cent respectively.
In Zeneca's other divisions, strong demand for herbicides drove a 17 per cent rise in profits from the agrochemicals operation. Rising raw materials prices squeezed the small speciality chemicals arm.
The company also remained tight-lipped about prospects for expanding its latest acquisition - 50 per cent of Salick, a US company that runs cancer clinics. Analysts believe the provision of care will be a profitable sideline for drugs companies, which face increasing pricing pressures in their core business.
Zeneca is, however, seen as less dependent on diversifications than many of its peers. It has a widely admired new drugs pipeline, including four treatments for cancer and a pill for asthma.