Mayne Pharma shares have soared after the company expanded its presence in the lucrative US market through the purchase of a suite of generic drugs.
Shares in Mayne gained 42 cents, or 28.3 per cent, to $1.905 after emerging from a trading halt during which the company completed an institutional share offer and placement to help fund the $US652 million ($A889 million) deal.
Mayne Pharma will significantly expand its US presence through the generic drug acquisitions from Teva Pharmaceutical Industries and Allergan.
It raised about $347 million under the institutional component of its share offer, at $1.28 per share.
About 99.9 per cent of eligible institutional shareholders took up the offer.
The placement, which was conducted via a bookbuild, attracted strong demand and raised $287 million at $1.50 per share.
A retail share offer, at $1.28 for each new share, opens on July 4 and closes on July 15.
"We are delighted with the exceptional support that our existing shareholders and new investors have shown," chief executive Scott Richards said.
"This acquisition is another significant step forward in the execution of our strategy to strengthen and grow our business in the world's largest pharmaceutical market."
Mayne will acquire 37 products approved by the US Federal Drug Administration and five products with filings for approval before the FDA.
The acquired products include oral contraceptives, cardiovascular products and therapeutics for the central nervous system.
Mayne said the acquired products were expected to generate stable revenue and earnings, and a pipeline of new products would provide a source of growth.
The acquisition transforms Mayne's generic products division into a top 25 player in the US retail generics market.
