Simon Nixon, the Co-Founder and Chairman of MoneySupermarket.com, announced plans to offload a near-15 per cent stake in the price comparison website this week, his first major disposal since the firm's stock-market flotation in 2007.Nixon, who helped found the business in 1993, is to offer up to 80m shares via a placing, representing around 14.8% of the company, an announcement on Wednesday said.He is expected to pocket around £166m from the transaction, as valued by the share price earlier this week.Nixon took up the Chief Executive Officer position when it went public in 2007, before becoming the Deputy Chairman in 2009.MoneySupermarket said that in line with his move to adopt a backseat sale - after recently changing from an Executive to Non-Executive Chairman - the placing will allow Nixon to "diversify his personal holdings", as well as normalise the firm's shareholding structure.Analyst Roddy Davidson from Westhouse Securities said that Nixon's sale should be viewed as a positive: "it should increase liquidity and ultimately the potential for a take-out, although is likely to cap short-term performance."The news came alongside the company's announcement to release a special interim dividend worth £70m to shareholders.