(Reuters) - American Airlines Group Inc (>> American Airlines Group Inc) said higher average fares per mile have boosted its revenue and profit expectations for the fourth quarter, a day after rival United Continental Holdings Inc (>> United Continental Holdings Inc) also raised forecasts.

Shares of top U.S. airlines rose on Friday, with American's up 4 percent and United's up 4.2 percent.

American, the world's largest airline, said on Friday it expects fourth-quarter unit revenue to range between a decline of 1 percent and an increase of 1 percent, compared with its previous forecast of a decline of 2.5 percent to 0.5 percent.

Unit revenue compares sales to how many seats an airline flies and how far it flies them.

The airline now expects pre-tax margin excluding items to be between 6 percent and 8 percent, up from its previous range of 5 percent to 7 percent.

United, the No. 3 U.S. airline by passenger traffic, also forecast on Thursday a higher profit margin in the fourth quarter as bookings strengthened and expenses related to employment benefits were lower than expected.

"United provided a solid upward guide to Q4 expectations last night, pushing consensus close the level where we initially began the quarter," JPMorgan analyst Jamie Baker said in a research note on Friday.

"Meanwhile, American’s updated guide this morning, also implies upside to consensus estimates and critically also opens the door to positive unit revenues in Q4."

(Reporting by Arunima Banerjee in Bengaluru and Alana Wise in New York; Editing by Saumyadeb Chakrabarty and Phil Berlowitz)