* Aussie index posts lowest close since May 8
* A2 Milk biggest drag in NZ index (Updates to close)
May 15 (Reuters) - Australian shares ended lower on Tuesday, led by losses for National Australia Bank NAB.AX and the nation's biggest telco operator Telstra TLS.AX .
The S&P/ASX 200 index .AXJO fell 0.6 percent, or 37.5 points, to 6,097.8, its lowest finish in a week.
NAB slipped to its lowest close since Nov 2016, down 3.4 percent as it traded ex-dividend, while Westpac Banking WBC.AX ended marginally lower. ANZ ANZ.AX and Commonwealth Bank CBA.AX rose 0.4 percent and 0.2 percent.
Telstra extended losses and finished the session near seven-year lows, down 5.6 percent.
The company issued a profit warning on Monday and said it expect conditions to remain challenging in 2019 with increased competition stemming from the National Broadband Network roll-out. BHP BHP.AX and Rio Tinto (LON:RIO) RIO.AX reversed course during the day and ended lower, in line with the downturn in copper, aluminium and oil prices. MET/L O/R
Automotive Holdings Group AHG.AX was the worst performer on the index, down 8.8 percent to its lowest since June last year.
The company said below-expected margin gains in the second half from its franchised dealerships and used car businesses will hit profits. Zealand's benchmark S&P/NZX 50 index .NZ50 closed marginally lower by 4.45 points to 8,708.78, snapping nine straight days of gains after hitting all-time highs in multiple sessions.
Dairy company A2 Milk ATM.NZ and Fisher & Paykel Healthcare were the biggest drags, down over 1.5 percent each.