BP (2) Image: BP

BP's profits fell by nearly 50% in the three months between July and September as falling oil and gas prices continue to take their toll.

The oil giant posted replacement cost profits of $1.23 billion (£802m), compared with $2.38bn in the same period. Revenues fell from $94.8bn to $55.9bn.

Oil prices have fallen by more than half over the the past year, from a peak of $115 per barrel last summer to around $50 for much of this year.

The market conditions have also reduced BP's capital expenditure. During the quarter, the oil giant spent $4.3bn, down by $1bn from last year. And for the whole year, BP is now expecting to spend around $19bn, compared with earlier estimates of $24-25bn.

BP also revealed that the total cost of the Deepwater Horizon oil spill in the Gulf of Mexico in 2010 would likely be around $55bn, higher than previous estimates. It comes after the firm agreed a $20bn settlement in the US.

"BP has successfully adapted to changing circumstances many times in its history and, in a hard time for the entire industry, I believe we will once again successfully take on today's challenges," said BP chief executive Bob Dudley.

"We are already in action, with a quality portfolio and clear plans for the future. I am confident BP will continue to deliver value into the years and decades ahead."