Activity in New Zealand's services sector declined further in April, with most indicators in the negative territory amid persisting economic challenges, according to the latest survey by BusinessNZ published Monday.

The BusinessNZ Performance of Services Index (PSI) fell to 48.5 in April from 48.9 in March. A reading below the 50-point mark points to contraction.

"[F]or all the commentary around the economic recovery, the PSI is a good reminder that current conditions are extremely challenging," said BNZ's senior economist Doug Steel.

"New Zealand's PSI remains weaker than all our key trading partners. At 48.5, it is consistent with a service sector still moving backwards," Steel added.

The activity/sales indicator stayed at 47.3, while the employment measure decreased to 48.2 from 50. Stocks/Inventories fell to 48.5 from 48.9, while supplier deliveries declined to 45.8 from 48.2.

The only indicator that yielded a positive read was new orders/business, which ticked up to 50.9 from 50.8.