Virgin Blue Holdings Ltd. reported a 0.5 per cent increase in its domestic passenger numbers and 18.7 per cent in its international passenger numbers for the month of April.

The domestic numbers are still 2.9 per cent down for the year to date, while the international numbers are up 32.5 per cent compared to the same period last year.

Domestic traffic measured by revenue passenger kilometres, increased by 1.3 per cent for the month, while capacity, measured by available seat kilometres, lifted 3.1 per cent.

International traffic is increased by 60.4 per cent while capacity increased by 41.9 per cent for April.

Earlier this month, Virgin Blue and Air New Zealand announced their intention to seek regulatory approval to create an alliance on the Trans Tasman. The proposed alliance will allow the airlines to strengthen their competitive offering on the Trans Tasman route and to collaborate on future routes and product planning, code sharing and frequent flyer program benefits.

Virgin Blue was named by the federal government as of four airlines appointed to supply domestic air travel to government agencies. Virgin Australia and Pacific Blue were named as among 13 airlines to supply international air travel services for the government.

Virgin Blue shares last traded at $0.42 each.