A $5 billion third-quarter profit from Chevron lifts the cumulative results of the five major oil companies that reported July through September earnings this week to more than $31.5 billion.

The industry benefited from oil prices that averaged more than $70 a barrel, as well as its ability to earn more money from gas production and sales.

Chevron's profits grew the fastest among its peer group, rising a whopping 40% from a year ago.

Chevron's results, released yesterday, marked the third time in the past year that its quarterly profits have hit a new high. The third-quarter figures were also far above analyst estimates, boosting Chevron shares by 18 cents to $67.68 on a day when the market benchmarks fell.

The boom times at Chevron and other major oil companies exasperated motorists and politicians as gasoline prices remained above $3 per gallon in many parts of the country before a recent decline eased some of the economic pain and frustration.

But the downturn in energy prices hasn't sapped the financial vigor of Chevron and its industry brethren.

Exxon Mobil, the only U.S. oil company larger than Chevron, posted a third-quarter profit of $10.5 billion - the second highest in its history.

Chevron's earnings of $5.02 billion, or $2.29 per share compared with profit of $3.59 billion, or $1.64 per share, at the same time last year.

Chevron boosted its earnings despite a slight decline in its revenue, which totaled $54.2 billion. That was down from $54.5 billion last year.

While more productive refineries contributed to Chevron's upturn, Oppenheimer analyst Fadel Gheit said Chevron reaped its biggest gains at the gasoline pumps. "They really cleaned up there," Gheit said.