Air China is to double flights from Heathrow to Beijing from October.
The expansion means there will be a total of 51 departures a week to mainland China from the London hub.
Air China’s flights will operate from the new Terminal 2, which is being used as the base for Star Alliance carriers at the airport.
The news came as Heathrow announced a 0.5% rise to a record 6.97 million passengers in July over the same month last year.
July 27 was Heathrow’s record busiest day, with 239,928 passengers passing through the terminals.
Within emerging markets, Mexico was up 15.4%, China rose by 10.4%, India was up 7.6%.
Heathrow CEO John Holland-Kaye said: “The doubling of Air China’s routes to Beijing represents a vote of confidence for T2.
“It’s also recognition that despite other UK airports having spare capacity, only Heathrow can deliver daily, direct flights to emerging economies that will help Britain win the global race for growth. Gatwick can’t, Heathrow can.”