Pfizer Chief Executive Ian Read said the U.S. drugmaker had contacted the British government on Monday about its desire to acquire AstraZeneca in a potential $100 billion deal to create a new drugs giant.
"We reached out to the UK government this morning. We've have some initial preliminary discussions," Read told reporters in a conference call.
"We want to have a conversation with the government about the excitement we have about combining these portfolios, the excitement we have about the strength of UK research," he said.
"This combination, if it occurs, would create domiciled in the UK the largest pharmaceutical company in the world and would bring an injection of about $100 billion into the UK economy."
The suggested deal has triggered worries about jobs in Britain's drug sector, viewed by the government as a key industry.
Read said he saw Britain as an attractive location for pharmaceutical research and manufacturing - helped by recent government tax incentives - but added he could not make any firm commitments on future investment or jobs.
Britain's finance minister George Osborne has indicated a hands-off approach to any deal between the two drugmakers, which he described on Friday as "a commercial matter between the companies".
(Reporting by Ben Hirschler, editing by Kate Kelland)