By Xiumei Dong

United Continental Holdings, Inc. and Southwest Airlines Co. both reported big fourth quarter earnings jumps Thursday, as the two carriers continue to benefit from falling oil prices.

In the latest quarter, Southwest’s net income climbed to $536 million, or 82 cents per diluted share, from the $190 million, or 28 cents per diluted share, in the year-ago quarter.

Revenue surged 7.5 percent, to $4.98 billion from $4.63 billion a year ago.

Southwest said that excluding special items, per-share earning were 90 cents, up from an adjusted 59 cents in last year’s quarter. The 90-cents-a-share result was in line with the estimate of analysts surveyed by Yahoo Finance.

“We continue to benefit from significantly lower jet fuel prices and our fleet modernization,” Gary Kelly, Southwest chairman of the board, president and chief executive offer, said in a prepared statement.

The Dallas load factor, or percentage of available seats filled, increased by 2.1 percentage points to 84.1 percent, from 82 percent in last year’s quarter.

For the full year, Southwest’s net earnings increased 92 percent, to $2.18 billion, or $3.27 per share, from $1.14 billion, or $1.64 per share. Revenue rose 6.5 percent to $19.82 billion from $18.61 billion in 2014.

In New York Stock Exchange trading, Southwest shares closed at $ 39.50, up 20 cents.

Fourth quarter per-share earnings ($)

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Chicago-based United reported fourth-quarter net income of $823 million, or $2.24 per diluted share, compared with $28 million in a year-ago quarter.

Revenue declined 3.0 percent, to $9.04 billion from $9.31 billion.

“The four primary factors we identified at the beginning of the quarter impacted our revenue performance as expected,” said Jim Compton, vice chairman and chief revenue officer of United Airlines. “a strong US dollar, the effects of lower oil prices, pressure as a result of margin accretive initiatives and competitive pricing actions.”

United said that excluding special items, per-share earnings were $2.54, compared to $1.20 in last year. That performance landed short of forecasts: Analysts surveyed by Yahoo Finance had been expecting United to report per-share earnings of $2.59.

United’s load factor increased by 1.0 percentage point, to 82.6 from 81.6 percent last year.

“The attacks in Paris put pressure on booking across the Atlantic during the weeks that followed the event,” said Compton.

United reported full-year net income of $7.3 billion, or $19.47 per diluted share. Annual revenue increased by 2.7 percent, to $37.86 billion from $38.90 billion

In New York Stock Exchange trading, United Airline shares closed at $45.33, up by 47 cents.

The entire airline industry is benefiting from the dramatic fuel price drop.

Fuel expenses for United Airlines were down by 36 percent, at $1.61 billion from $2.53 billion in the year-ago quarter. Southwest’s fuel cost went down 31.6 percent, to $789 million from $1.17 billion in the year-ago quarter.

Both airlines also took advantage of the cost cut in fuel expense to upgrade their fleets.

United announced on Thursday it is buying 40 new Boeing 737-700 aircraft which will enter the fleet beginning in mid-2017 to replace some of the smaller, older planes operated by its regional carriers.

Southwest is scheduled to add 33 new Boeing 737-800s, as it accelerates the retirement of its old planes.