LONDON — Pharmaceutical giant Pfizer said Friday that it hasn’t given up on a deal after British drugmaker AstraZeneca flatly rejected its latest takeover bid, worth $106 billion.

Pfizer Inc., the world’s second-biggest drugmaker by revenue, made a third unsuccessful attempt for its London-based rival Friday with an offer of 50 pounds ($84) per share in cash and stock – a 7.3 percent increase from its last bid. AstraZeneca Plc, the No. 8 drugmaker, called that inadequate and said the potentially lucrative “pipeline” of new drugs it is developing would be disrupted by a takeover.

Pfizer expressed disappointment, saying in a statement that a “friendly, negotiated transaction” would be best for shareholders of both companies. Pfizer said it is considering its options.

Proposed deals to swap assets or acquire other companies are roiling the pharmaceutical industry. Many companies are narrowing their product and research focus to their areas of expertise to save money. They are cutting costs as cheaper generic competition slashes sales of off-patent medicines that had been top earners. Pfizer’s revenue has dropped sharply amid generic competition to multiple drugs, particularly its cholesterol blockbuster, Lipitor, which once brought in $13 billion a year.

Pfizer’s bid for AstraZeneca would give it access to promising assets, particularly in immuno-oncology, new types of cancer drugs that work by boosting the immune system. Analysts say the deal also gives Pfizer tax advantages. They estimate Pfizer has earned and held $30 billion to $70 billion in cash overseas, on which it would have to pay taxes at relatively high U.S. rates should it be brought back.

“Once the cash is offshore, the potential tax cost of repatriating it to the U.S. makes it much more attractive to find other homes for it – such as making foreign acquisitions,” said tax specialist Heather Self of the law firm Pinsent Masons.

The deal would be the biggest foreign takeover of a British business. Critics fear the takeover could mean big job cuts and potential loss of stature in the country’s science sector.