The pre-tax loss was far more than the $418 million industry analysts had predicted, The Times of London reported.
Revenue for the six-month period also fell, dropping 13.7 percent compared with the same period of 2008.
Chief Executive Officer Willie Walsh said airline's 12-month revenue would likely be down by $1.65 billion by the end of the year.
"Our costs are some $663 million lower and manpower has been cut by 1,900 through reduced overtime, increased part-time and targeted voluntary redundancy," Walsh said.
Nevertheless, British Airways would further reduce is payroll by 6 percent by March, he said.
He said the airline would also make "permanent changes to the way we run our business."