SkyCity has increased its stake in Hamilton’s Riverside Casino by buying up Tainui’s 15 percent holding for $10.5 million. The purchase means SkyCity now has 70 percent of the business. Hamilton-based Perry Developments owns the remaining 30 percent. SkyCity Entertainment Group Managing Director Evan Davies says developments such as the recently announced expansion of Hamilton Airport have encouraged the company to invest further in Waikato. The deal is subject to regulatory approval.