Auckland Council has become the first local body to secure the ability to borrow money overseas.
The country's largest local body will have access to up to $3.2 billion, in a deal arranged by the bank HSBC.
The council says it has so far made no firm plans to borrow overseas.
A change to legislation has loosened restrictions that meant local bodies had to borrow within New Zealand.
Auckland Council has been put on notice of a possible ratings downgrade, to the third highest level, with the agency Standard & Poor's, noting plans to increase debt for major insfrastructure projects.