The bookbuild closed oversubscribed with the facility upsized from the original amount of $280 million.
Commonwealth Bank of Australia and the Hongkong and Shanghai Banking Corporation acted as mandated lead arrangers and bookrunners of the facility.
The facility comprises three tranches covering working capital, bank guarantees and equipment financing.
Macmahon chief financial officer Sybrandt van Dyk said the new facility provided the company with stability and certainty of funding.
"This facility refinances the company's existing term debt and bank guarantees and will also be utilised to fund the purchase of new and used equipment, general corporate purposes and working capital needs,” he said.
Previous financiers Caterpillar Financial Australia, GE Capital and Taiwan Business Bank were involved, while the company incorporated new parties into the facility.
"In addition to our existing lenders, we are very pleased to have the support of several new financiers in the syndication, namely Hua Nan Commercial Bank, Taiwan Cooperative Bank, Mega
ICBC and Macquarie Bank," van Dyk said.
The company last month posted a full-year profit of $30.4 million on revenue of $1 billion.
Macmahon is forecasting FY15 revenue of between $750 million and $1 billion.
The company’s order book currently stands at $2.6 billion and it is tendering for around $2.3 billion of new work.