SIM Technology's (HKG:2000) revenue from its core business fell 8.8% to HK$29.2 million in May from HK$32.1 million a year prior, according to a Wednesday Hong Kong bourse filing.

The decrease came amid changes by the firm's customers in the delivery time of their purchase orders.

The mobile communications company recorded total revenue of HK$32.2 million in the month, up 42% from HK$22.7 million in April.

For the five months ended May 31, revenue slipped 16% to HK$148.2 million from HK$176 million in the year-ago period.