British Airways carried 2.9 percent fewer passengers in August compared with the year before and said its overall summer performance had been weaker than last year.

BA carried 3.15 million passengers last month, down on August 2009, while its load factor fell 0.3 percentage points to 84.4 percent.

It said first and business-class travel -- the most profitable part of its passenger business -- fell 1.4 percent but that non-premium traffic was down 3.1 percent.

"Market conditions remain as previously anticipated, with overall summer volumes slightly lower than the peak levels seen last year," BA said in a statement.

BA, which enjoyed a strike-free August, could face more industrial action over the coming weeks, with the union considering balloting members over a fresh wave of strikes.

The Unite union, which represents BA cabin crew, is due to hold a mass meeting of its members in the southern English town of Kemptown on Monday.

The airline, whose merger with Spain's Iberia was cleared in July, said the year-on-year reduction in premium traffic was due to promotional activity in its premium cabins last year.