* Lynas among top losers on Aussie benchmark
* Challenger marks worst day since March 2020
* NZ shares decline 0.7%, Napier Port down (Updates to close)
By Vasudha Kaukuntla
April 20 (Reuters) - Australian shares snapped a five-day rally on Tuesday as tech stocks tracked an overnight decline in U.S. markets, and earnings-driven losses in fund manager Challenger and rare earths miner Lynas weighed.
The S&P/ASX 200 .AXJO fell 0.7% to 7,017.80, its worst session since March 30. All sub-indexes ended in negative territory.
All three major Wall Street indexes ended lower on Monday, with the tech-heavy Nasdaq .IXIC slipping nearly 1%. .N
"The benchmark is lower tracking Nasdaq which is down quite a bit with the tech-heavy stocks. We are certainly more affected by financials, miners and tech sectors on the local index," said Dale Raynes, associate director at CPS Capital.
Tech stocks .AXIJ fell 1.2%, dragged by Altium Ltd ALU.AX which was down the most at 5.2%.
Sector heavyweight Afterpay APT.AX lost 0.8%. The buy-now-pay-later giant said it was exploring a U.S. listing after North America became its biggest market. stocks .AXFJ gave up 0.9%. Challenger CGF.AX plummeted 15.8%, its worst day since March 2020, as it forecast annual profit at the bottom end of its guidance range. .AXMM eased 0.2%, with Lynas LYC.AX slumping 8.5% after its third-quarter revenue and sales volume of rare earth oxides fell from the prior quarter, partly due to the Suez Canal blockage in March. said losses in Lynas and Challenger were having a particularly pronounced affect on the market due to a lack of other catalysts.
New Zealand's benchmark S&P/NZX 50 .NZ50 fell 0.7% to 12678.55. Port and harbour operator Napier Port NPH.NZ declined the most, falling 4.2%. ($1 = 1.2832 Australian dollars)