The operator said 22% of the funds would be used for the DBCT expansion, with 55% put towards its purchase of UK-listed gas distributor International Energy Group (IEG) and the remainder used for debt reduction and other acquisitions.
Prime, an affiliate of investment and advisory firm Babcock and Brown, said the funds would be raised in a share auction to institutional investors and a non-renounceable rights issue.
"Prime Infrastructure anticipates further opportunities arising in the UK, including the opportunity to purchase other assets similar to IEG's UK Independent Gas Transporters business," Prime told investors.
The share auction took place yesterday, with shares priced from $A1.40.
"Based on Dalrymple Bay Coal Terminal user indications and demand and supply forecasts, an increase in capacity to over 60 million tonnes per annum is required," Prime said.
Work is currently underway to expand DBCT's capacity from 54.5Mt throughput per annum to 60Mt.
Prime units closed at $A1.57 on Wednesday and are on a trading halt until the share auction is completed, while Babcock & Brown shares rose 2.6% to $A10.16 in early afternoon trade on Thursday in a higher overall market.
