The company, which has an annual turnover of £878m, announced its intention to float on the stock market last week.
CDR won the account after a head-to-head battle with Brunswick and intends to launch an offensive on the business press to attract institutional investment.
Evolution Beeson Gregory is the nominated adviser sponsoring the IPO.
CDR will also be responsible for the Costa Rica-based company’s day-to-day financial PR, including its investor relations, calendar work and corporate positioning.
CDR executive director Ginny Pulbrook and director Victoria Brough will lead a four-strong team on the account, reporting to Bet on Sports chief executive David Carruthers.