Markel, an insurance company, completed the acquisition of a 49% stake in Certa, a tax MGA. Financial terms were not disclosed. "Markel has provided capacity to Certa from day one, and in a short period of time Certa has become a market-leader in its specialist sector. We believe the business has plenty of headroom for growth in the coming years as the tax sector continues to mature," David Sawyer, Markel Divisional Managing Director of Professional and Financial Risk.