In December 2000, Sampo Insurance Company and Leonia, the successor of Postipankki, merge into Sampo-Leonia Financial Group. The main business areas of the Group are long-term savings, banking, investment banking and property and casualty insurance.

The Extraordinary General Meeting of Sampo-Leonia approves the plan to merge Mandatum Bank into Sampo-Leonia Group. Mandatum Bank is merged into the Group in February 2001. Björn Wahlroos, Chairman of Mandatum Bank directorate, begins his work as Group CEO and President of Sampo-Leonia Group. In April the Group adopts the name Sampo.

Over the years, several property and casualty insurance companies have merged into Sampo. The largest structural arrangement in the property and casualty insurance industry takes place in the beginning of 2002 when Sampo combines its property and casualty insurance operations with If, a property and casualty insurance company founded by the Swedish Skandia Insurance Company and the Norwegian insurance company Storebrand. Following the transaction, Sampo owns 38 percent of If's stock. In addition to Sampo, the owners of the company include Skandia, Storebrand and the Finnish Mutual Pension Insurance Company Varma.

In 2004, If, the leading property and casualty insurance company in the Nordic region, becomes a fully owned subsidiary of Sampo. If's market share in the Nordic countries is more than 20 percent. In Finland, If is the largest insurance company with its 30 percent market share. If operates in Finland, Sweden, Norway, Denmark and the Baltic countries. Following the transaction, Sampo has three main business areas: property and casualty insurance, banking and long-term savings.

Sampo's banking operations are transferred to a Danish ownership in early 2007 when Sampo divests the entire share capital of Sampo Bank to Danske Bank. After the divestment, Sampo's main business areas are property and casualty insurance and life insurance. Sampo plc, the parent company of the Group, manages a significant investment portfolio following the divestment of Sampo Bank Group.

In the autumn of 2008, Sampo's subsidiary, Sampo Life Insurance Company changes its name to Mandatum Life Insurance Company. The company was established in 1997 and it operates in Finland, Estonia, Latvia and Lithuania. Mandatum Life focuses on unit-linked insurance. It has a significant market share in corporate pension policies. The company works in close cooperation with Mutual Insurance Company Kaleva and If.

In connection with Sampo's Annual General Meeting in 2009, Björn Wahlroos, Group CEO and President since 2001, is elected as Chairman of the Sampo Board. Long-time deputy CEO Kari Stadigh succeeds Wahlroos. Stadigh is also Managing Director of Sampo plc, the parent company of the Group, and Chairman of the Board of If, Mandatum Life and Mutual Insurance Company Kaleva.

Sampo plc has increased its ownership in Nordea, the largest Nordic banking group since 2006. In 2009 Sampo's holding in Nordea exceeds 20 per cent. As a result, Nordea becomes Sampo's associated company.