"This is consistent with global trends where large companies are issuing bonds and decreasing their dependence on banks' economic issues."
While bigger companies used a range of funding sources the situation was almost reversed for the next 25 largest companies where most - 18 out of 25 - were solely reliant on bank debt.
Last year was a big year for listed companies raising debt on the market and Chapman Tripp is predicting another two to three companies will enter the debt capital markets for the first time in 2019.
"However, most entities still obtain a fairly high proportion of their debt from New Zealand banks, meaning they remain reliant on banks.
"That will continue in the next 12 months given the flexibility of bank funding compared to the other sources and the relative ease of obtaining bank funding in New Zealand."
That was unlikely to change while bank funding remained available, the report noted.
It also found that most of the top 50 companies had more than one bank providing debt funding.
"Some listed entities have only one bank but we would expect that to change as these businesses grow."