LONDON (Reuters) - Advisers could pocket up to $100 million in fees from Johnson & Johnson's (>> Johnson & Johnson) $30 billion acquisition of Swiss biotech firm Actelion (>> Actelion Ltd), the largest takeover of a European healthcare business in more than a decade.

Four investment banks will share the advisory pot; J&J could cough up $30-$40 million in fees to its advisers, Lazard and Citi, while Actelion is expected to pay $45-$60 million to Bank of America and Credit Suisse, according to estimates from Thomson Reuters/Freeman Consulting.

Lazard, which acted as lead adviser to J&J, is set to earn the most, followed by Bank of America, which acted as Actelion's lead adviser.

The deal is the biggest takeover with a European pharma business as target since Sanofi-Synthelabo acquired rival Aventis 13 years ago to forge what is now Sanofi (>> Sanofi).

It ranks as the third biggest globally in any sector this year, after British American Tobacco's (>> British American Tobacco plc) $49.4 billion acquisition of U.S. rival Reynolds American Inc (>> Reynolds American, Inc.) and a $49 billion all-share merger between Italy's Luxottica (>> Luxottica Group SpA) and France's Essilor (>> ESSILOR INTL.) to create a global eyewear powerhouse.

The sale of Actelion, announced on Thursday after weeks of exclusive negotiations, is yet another windfall for M&A bankers, showing that Europe remains an attractive region for corporate deals despite uncertainty over Brexit and upcoming elections in France, Germany and the Netherlands.

Global M&A activity fell 16 percent in 2016, while acquisitions of European companies dropped 13 percent to $756 billion, according to Thomson Reuters data. Advisory fees attached to global M&A deals fell 2 percent to $27 billion.

(Editing by Pravin Char)

By Clara Denina