Nov 15 (Reuters) - Commonwealth Bank of Australia , the country's largest bank, on Tuesday reported better-than-expected cash earnings for the first quarter, helped by lending growth and rising interest rates.

Australian banks are benefiting from an aggressive monetary tightening path taken by the central bank to contain runaway inflation, improving their lacklustre margins and income from high interest rates.

"The economy has shown resilience in the face of growing cost of living and interest rate pressures and despite these near-term challenges we remain optimistic on the medium- to long-term outlook," Chief Executive Officer Matt Comyn said.

The Sydney-based lender's net interest income grew 16% during the reported quarter on the back of higher deposit earnings, volume growth across core products in home lending, business lending and household deposits during the period.

Cash profit, which excludes one-offs and non-cash accounting items, rose to A$2.50 billion ($1.68 billion) in the three months ended Sept. 30, compared with A$2.20 billion a year ago and a Visible Alpha consensus of A$2.33 billion.

The bank's home lending portfolio grew 6.3% during the quarter from a year ago, while business lending and household deposits jumped 12.6% and 8.6%, respectively.

CBA, which has a quarter of the Australian mortgage market share, said late and impaired loans remained low due to low unemployment levels. Its arrears stood at multi-year lows of 0.88% for personal loans and at 0.44% for home loans.

However, analysts believe rising interest rates, inflation, and a rebound in unemployment could push those figures higher.

Operating expenses grew 4.5% excluding remediation costs, driven by wage inflation and additional working days.

The other three of the 'big four' Australian lenders: National Australia Bank, Westpac Banking Corp, and Australia and New Zealand Banking Group, have earlier warned of rising costs in the coming financial year. ($1 = 1.4901 Australian dollars) (Reporting by Sameer Manekar in Bengaluru; Editing by Shailesh Kuber)