The regional agency won the business after separate pitches for the accounts against undisclosed agencies.
Ice.lolly.com was previously held by Leeds-based agency England while online media for Genting Casino was handled by MediaVest in Leeds.
David Bryan, head of marketing at Genting Alderney, operator of Genting Casino, said: "Universal McCann Central clearly understood the market, provided us with some great consumer insight and formulated an integrated, ROI driven marketing strategy that will help to establish Gentingcasino.com in a very competitive market."
The wins comes as the agency expands its team, appointing Sushma Sharma as media planning director and James Wood as acquisition planning director and promoting Amy Eddy to the role of digital media director.
Sharma joined from Universal McCann South Africa, Woods from Leeds-based England, and Eddy was previously digital manager.