SAO PAULO, Nov 24 (Reuters) - LATAM Airlines was the market share leader among companies flying between Brazil and the U.S. in the quarter ended in October after resuming non-stop flights to Los Angeles, data from local authority ANAC showed on Friday.

The Chile-based company, which leapfrogged U.S. majors American Airlines and United Airlines, transported more than 260,000 passengers between the countries in the period.

Average load factor in those flights, LATAM told Reuters, reached 89%.

LATAM had last led the ranking for three months in a row between November 2019 and January 2020, before the COVID-19 pandemic disrupted air travel around the world, ANAC figures show.

Brazil has the U.S. as its No. 1 market for international flights in number of passengers transported, with an 18% share so far this year, above Argentina (15%) and Portugal (12%).

"The leadership reflects the sustainable recovery of our international operations and the first year of our joint venture with Delta," LATAM Brasil sales director Aline Mafra said in a statement to Reuters.

The results, according to ANAC, secured LATAM a 26% market share for flights between the two most populous countries in the Americas in the August-October period, above American Airlines' 22% and United Airlines' 20%.

Year to date, American Airlines still leads the ranking with a 23.7% market share, slightly above LATAM's 22.4%, considering the number of passengers transported.

LATAM resumed flights between Sao Paulo and Los Angeles in August, making it the sole non-stop flight between Brazil's largest city and the U.S. West Coast, and hopes to transport more than 110,000 people per year in the route.

It had also launched Sao Paulo-Boston flights last year, saying 74,000 people have flown between the two cities so far, with an average load factor of 80%. The carrier also operates flights to Miami, Orlando and New York.

LATAM and Delta have been working on implementing their joint venture since October last year, and claim that so far they have managed to increase their capacity by 75%.

Delta in December is set to relaunch flights from Rio de Janeiro to New York and Atlanta. In 2023 the U.S. carrier has so far ranked fifth in U.S.-Brazil traffic, also lagging behind Azul. (Reporting by Gabriel Araujo; Editing by Steven Grattan and Marguerita Choy)