The Australian Competition and Consumer Commission said today it had granted interim authorisation to the airlines to expand their alliance.

The airlines had asked for a 10-year expanded business deal, allowing them to co-ordinate flights on the trans-Pacific route and lift capacity between Australia and the US by around 9 per cent.

ACCC commissioner Dr Jill Walker said the authorisation would likely lead to additional capacity between Sydney and Los Angeles and greater competition and capacity between Sydney and San Francisco.

“This is likely to result in benefits to passengers that wish to use these services,” Dr Walker said.

“Granting interim authorisation is unlikely to have any permanent impact on the market that could not be reversed in the event final authorisation is not granted.”

The Qantas-American Airlines alliance was first given the green light by the watchdog in 2011 for a period of five years. The airlines have since sought permission for an expanded alliance.

Air New Zealand was the sole voice protesting against the deal.

The airline made a submission to the ACCC arguing it was inappropriate to grant authorisation without a full analysis of the impact of the agreement. Air NZ attracts Australian passengers onto its trans-Pacific flights by way of a stop in Auckland.

Interim authorisation is not indicative of whether or not final authorisation will be granted.

Qantas (QAN) said customers will soon be able to start booking direct flights to San Francisco for travel from December 18 — the most popular onward destination for Qantas customers travelling to the US.

Qantas will initially operate on peak days and ramp up to six flights per week by January next year.