The Competition Commission found that two competing travel service providers - Gray Line Tours of Hong Kong and Tink Labs - operated a cartel to fix or control prices of tourist attractions and transportation tickets sold at the hotels.

Upon investigation, the commission found that between March 2016 and May 2017, the two agreed to fix the prices of tourist attractions and transportation tickets sold at various hotels in Hong Kong, including the six hotel groups.

"They [hotel groups] acted as facilitators by passing on pricing information between these two competitors in circumstances where they had actively contributed to the implementation of the price fixing agreement," the commission said.

"We therefore had reasonable cause to believe that the arrangement had the object of harming competition in Hong Kong in contravention of the First Conduct Rule of the Competition Ordinance."

Named and shamed were China Asia Property, operator of City Garden Hotel; Harilela Hotels, owner of Holiday Inn Golden Mile; Holiday Inns Crowne Plaza (Hong Kong), operator of Holiday Inn Golden Mile; and Hotel Panorama Company, operator of the former Hotel Panorama.

Also included were The Hongkong Hotel, The Marco Polo Hotel (Hong Kong), The Prince Hotel and Wharf Hotels Management, owners and operators of the Marco Polo Hongkong Hotel, Marco Polo Gateway and Marco Polo Prince respectively, as well as Royal Plaza Hotel Management, Leverson and Royal Park Hotel Management, operators of Royal Plaza Hotel, Royal View Hotel and Royal Park Hotel.

The last was Imperial Tours, a tour counter operator inside the premises of Holiday Inn Golden Mile.

Commission chairman Samuel Chan Ka-yan said this is the first time his agency has pursued facilitators of cartel conduct since the commission was set up in 2012.

"This will drive home the message that not only cartelists, but third parties who facilitate anti competitive conduct between competing businesses, may also be subject to the commission's enforcement action," Chan said.

In the infringement notices, all seven parties admitted that they had contravened the ordinance and promised to take concrete measures to effectively enhance competition compliance within their respective businesses, according to the commission.

An infringement notice requires a person to commit to complying with the notice's requirements in return for not facing prosecution by the watchdog.

"After taking into consideration a number of factors, including the nature of their conduct as facilitators, as well as their early and active cooperation with our investigation, we consider the use of infringement notice as an enforcement outcome to be appropriate and proportionate to the circumstances in this case," the commission said.