Beach Energy has made a $1.585 billion bid to acquire Lattice Energy.
Lattice is the conventional oil and gas business of Origin Energy and will increase Beach's proved reserves by 200%.
The deal will also see Origin receive a "significant portion" of Lattice's gas supply from its east coast reserves, according to Bloomberg.
The underwriters, Credit Suisse, Goldman Sachs and UBS, have acted on both deals providing the funding for the acquisition - a $1.575 billion new senior secured syndicated debt facilities deal and a $301 million accelerated non-renounceable facilities offer.
Credit Suisse and Luminis Partners provided financial advice to Beach.