Mylan, which makes about 1,400 medications, offered $205 a share in cash and stock for Perrigo, according to a statement.
That represents a 25% premium over Tuesday’s closing price for Perrigo, which makes a range of products including skin gels, injectables and nasal sprays.
Arthur Shannon, a Perrigo spokesman, couldn’t immediately be reached for comment.
The deal would be Mylan’s biggest, more than four times the size of anything else it has attempted.
Mylan’s bid would add to a record period of consolidation in the pharmaceutical industry. Mylan agreed last year to acquire non-US operations of Abbott Laboratories for $5.3bn as part of a plan to move its tax address to the Netherlands.
Perrigo completed a similar tax manoeuvre in 2013, acquiring Elan so it could be domiciled in Dublin. Both companies’ operating headquarters remain in the US — Mylan’s in Canonsburg, Pennsylvania, and Perrigo in Allegan, Michigan.
Mylan surged 14% to $68.10 yesterday in New York. Perrigo jumped 24% to $205.54, after earlier reaching $215.73.
In an April 6 letter to Perrigo chief executive Joseph Papa, Mylan chairman Robert Coury called the deal a natural fit that would create a company with about $15bn in sales.
“A combination of Mylan and Perrigo offers clear and compelling strategic and financial benefits. This is the right time for our two companies to move forward together, and Mylan and our board are firmly committed to making this combination a reality,” Coury wrote.
Coury offered to make Papa co-chairman of the combined company, with Mylan CEO Heather Bresch and president Rajiv Malik keeping their roles. Coury proposed that other top Perrigo executives join as well.
Generic drugmakers have been actively consolidating recently and moving into new areas.
Mylan’s rival Teva Pharmaceutical Industries agreed to buy Auspex Pharmaceuticals for about $3.5bn in March, giving it drugs that curb tics and other movement disorders.
Actavis agreed to pay about $66bn for Allergan, the maker of anti-wrinkle treatment Botox, late last year.
Last year, generic drugmakers announced or completed more than $100bn in deals.