China Southern Airlines and Virgin America have signed a code-sharing agreement to ease travel for passengers flying the two airlines.

Under the agreement, announced in a statement on Dec 29, China Southern will place its two-digit airline code (CZ) and flight numbers on Virgin America routes operating from Los Angeles and San Francisco - including West Coast flights to and from Boston, Chicago and Washington.

The code-share arrangement allows a one-stop booking process, a single ticket and one-stop check-in, including baggage handling, for the trip.

Virgin America, based in Burlingame, California, said the agreement was unique in that China Southern is the only airline offering non-stop service between Guangzhou and Wuhan, Hubei province, and the US.

"We are thrilled to expand our network further into the United States with Virgin America," said Zhao Xiaosong, China Southern senior vice-president of international affairs and alliances. "The United States is a substantial market for us, and through this partnership, we could offer our passengers more travel destinations via Guangzhou."

China Southern, headquartered in Guangzhou, Guangdong province, has daily flights from Guangzhou to San Francisco (three flights a week with one stop in Wuhan); 10 flights per week from Guangzhou to Los Angeles; and daily flights from Guangzhou to New York.

China Southern, established in 1991, is one of the "Big Four" mainland carriers (along with Air China, China Eastern and Hainan Airlines) with more than 100,000 employees worldwide. China Southern was ranked first in Asia and third in the world in traffic volume in 2014.

"China is a significant inbound and outbound tourism market, and we are extremely pleased to partner with China Southern, Asia's largest carrier by fleet size, and an airline that shares Virgin America's commitment to providing excellent, guest-focused service," said Adam Green, Virgin America's director of network planning.