High oil and gas prices and bigger profit margins in refining helped the British energy giant BP PLC (BP) nearly double its third-quarter earnings.

However, the company also warned Tuesday that it would have to spend more on its business next year because of the weak U.S. dollar and continued inflationary pressures in some markets.

BP said it earned $4.48 billion for the three months ending Sept. 30, up from $2.34 billion for the same period a year ago. Revenues rose to $73.85 billion from $59.16 billion a year ago.

"This has been another strong performance against the backdrop of strong global demand," said BP chief executive John Browne.

That demand was underpinned by soaring crude oil prices.

The price of benchmark North Sea Brent crude (search) — propelled by factors including the loss of U.S. production following Hurricane Ivan, low inventories and limited spare capacity — averaged $41.54 a barrel in the second quarter. That was more than $6 per barrel higher than second quarter prices, Browne said.

Exploration and production, BP's biggest business, posted a 30 percent jump in profits to a record $5.14 billion as the company reaped benefits from its tie-up with Russian oil group TNK.

BP's refining marketing division was the top performer, recording an 89 percent leap in operating income to $1.3 billion.

Refining margins slipped from record levels in the second quarter but remained high due to strong growth in demand and low stocks, BP said.

The overall result was slightly lower than analysts expected and shares in BP were down 7 pence at 530.5 pence ($9.75) in afternoon trading in London.

"Analysts always look to be surprised on the upside and these results actually haven't done that. There will be a few disappointed people out there," said Zac Philips, of brokerage Teather & Greenwood.

The profits were curbed by an almost 50 percent increase in taxes paid to $2.11 billion during the quarter from $1.43 billion a year earlier.

Browne also warned that capital spending in 2005 was expected to be around $14 billion, above the company's previous forecast of around $12.5 billion to $13 billion, because of the weak U.S. dollar and inflationary pressure in the market price of capital goods such as steel, which is used in pipelines and oil rigs.

Excluding stock holding gains for the period, BP reported what it calls a replacement cost profit of $3.46 billion for the quarter, up from $2.26 billion a year earlier. BP said the replacement cost result strips out fluctuations in the value of stock holdings, and hence gives a better picture of BP's current financial position.

BP also reported a pro forma net profit, which it said excludes losses or gains from the sale of assets or termination of operations, of $3.94 billion, up 43 percent from $2.76 billion a year ago. That was lower than analysts expected.

BP produced 3.91 million barrels of oil and gas a day, up from 3.5 million a year earlier, the company said. It has a target to produce an average of more than 4 million barrels a day this year, which would be up 11 percent from 2003.

Browne said the outlook for the rest of 2004 will depend on how quickly U.S. production recovers after Hurricane Ivan and the strength of oil demand growth.

Economic recovery in the United States appeared to have gathered speed in the third quarter, but Europe was failing to keep pace, he said.

For the first nine months of the year, BP reported a profit of $13.2 billion, up from $8.15 billion a year earlier. Nine-month revenue came to $214.49 billion, up from $176.38 billion a year ago.