News: NAB UPDATE 1-National Australia Bank's first-half cash profit jumps 17%

(Adds detail on results, context)

May 4 (Reuters) - National Australia Bank (NAB) on Thursday reported a 17% jump in its first-half cash profit, as the country's second-largest bank continued to benefit from a high interest rate macro environment which in turn boosted its margins.

Australian banks' coffers are swelling up on the back of surging interest rates since last year, although increasing living costs, softening home prices and a cooling economy pose threat to credit growth and paves way for more bad debt.

NAB said net interest margin - the difference between interest earned from lending and paid for deposits - came in at 1.77% for the half year.

NAB reported cash earnings of A$4.07 billion ($2.72 billion) for the six months to March 31, compared with A$3.48 billion a year earlier. Analysts on average had expected A$4.15 billion, according to Refinitiv data.

The lender declared an interim dividend of 83 Australian cents per share, up from 73 Australian cents apiece a year earlier.

($1 = 1.4990 Australian dollars)