SINGAPORE (AFP) - Singapore Airlines said on Wednesday its financial first quarter net profit plunged 71.4 per cent from the previous year, weighed down by lower passenger and cargo revenue.

Net profit in the three months to June came in at $34.8 million, down from $121.8 million in the same period last year, the national flag-carrier said in a statement.

Group revenue fell 4.1 per cent to $3.68 billion.

"Passenger revenue declined year-on-year on the back of weaker yields amid intense competition, and unforeseen events that depressed travel demand in some key Asian markets," it said, without specifying details on what events had caused a drop-off in passengers.

SIA said cargo revenue also fell "as the airfreight market continued to be affected by excess capacity".

It added that losses from associated companies, in particular budget carrier Tiger Airways, contributed to the decline in net profit.

"The outlook for the air transportation industry has become more challenging with continuing uncertain global economic climate, geo-political concerns in the region and elevated fuel prices," it said.