Recasts with CBA and NAB commentary

By Christine Chen and Byron Kaye

SYDNEY, March 18 (Reuters) - A trade war sparked by U.S. President Donald Trump's tariffs may drive up global inflation, stoke market volatility and slow economic growth, the CEOs of two top Australian banks said on Tuesday, but added Australia was insulated from the disruption.

The heads of No. 1 retail lender Commonwealth Bank of Australia CBA.AX and No. 1 business lender National Australia Bank NAB.AX told a conference the new U.S. administration's protectionist policies would likely strain the global economy in the medium term with higher costs and lack of certainty.

But Australia's roughly $15 billion a year in exports to the U.S. was small compared to its overall export trade, so the country was better placed than Canada, which sells 85% of its exports to the U.S., the financial leaders added.

"There's certainly risk to the downside, around slowing global growth," CBA CEO Matt Comyn told the Australian Financial Review Business Summit in Sydney, adding U.S. tariffs would mean "inefficiencies in trade (and) therefore more inflation".

CBA had reported a "pronounced uptick" in mortgage applications since the Reserve Bank of Australia cut interest rates last month for the first time since November 2020 to 4.1%, Comyn's head of retail banking Angus Sullivan told the conference earlier.

NAB CEO Andrew Irvine said the rate cut had been an "exhale of breath" in the economy, but "tariff madness" under Trump may lower the chance of further cuts this year. Currently NAB expects two 25-basis point cuts in 2025.

"We're not an island," Irvine told the conference. "If this tariff madness does happen, we could be at the end of (rate) reductions."

(Reporting by Christine Chen and Byron Kaye in Sydney; Editing by Himani Sarkar and Michael Perry)

((christine.chen@thomsonreuters.com; +61 2 9171 7119;))