Shares of Southwest Airlines Co. surged 1.9% in premarket trade Thursday, after the air carrier reported a fourth-quarter profit and revenue that beat expectations, while load factor fell short. Net income fell to $654 million, or $1.17 a share, from $1.7 billion, or $2.94 a share, in the same period a year ago. Excluding non-recurring items, adjusted earnings per share came to $1.17, above the FactSet consensus of $1.07. Total revenue rose 8.5% to $5.70 billion, topping the FactSet consensus of $5.67 billion, as 8.6% growth in passenger revenue to $5.32 billion beat expectations of $5.27 billion. Load factor fell 1.5 percentage points to 83.5%, below the FactSet consensus of 84.4%. Revenue per available seat mile increased 1.8%, as passenger revenue yield increased 3.7%. Operating expenses per ASM rose 1.5%, due primarily to higher jet fuel prices. The stock has gained 2.2% over the past three months, while the NYSE Arca Airline Index has climbed 5.2% and the S&P 500 has lost 0.7%.