Party people: AmCham's James Thompson and InvestHK's Mike Rowse get geared up for next month's Rolling Stones concerts.

More than 10% of tickets for the two Rolling Stones concerts at HK Harbour Fest were snapped up within 90 minutes of going on sale today.

Tickets are "selling like hot cakes", InvestHK Director-General of Investment Promotion Mike Rowse said.

Although there is still more than three weeks until the shows, Mr Rowse said organisers are very encouraged by the sales and believe the event will be very successful, putting Hong Kong back into the international spotlight.

On the confusion over the concerts, Mr Rowse said co-organisers the American Chamber of Commerce and the band reached a broad understanding in August that the group will perform.

With the contract agreed by both sides, AmCham signed it and paid the 50% deposit on October 2.

However, the Stones could not sign the contract before the deadline due to a hold-up in arrangements for their Mainland concerts.

With no alternative, AmCham and InvestHK decided to take the contract "off the table in a non-confrontational way" last week.

The group then decided to sign the contract again.

"There is no problem with the Hong Kong contract itself. It is a done deal," Mr Rowse said.

He also reiterated that InvestHK is the controller for the $1 billion maximum Government undertaking for the festival, and it will submit a full financial report to the Legislative Council as soon as possible.