Life insurance group Aviva has confirmed it is to sell a minority stake in its Dutch insurance business Delta Lloyd through a float on Euronext in Amsterdam.No more details were released, but weekend reports had suggested Aviva would sell between 30-40% of Delta and value it at about £4bn.In a brief statement this morning, Aviva said that the IPO of Delta would give it flexibility to pursue balance sheet restructuring opportunities or to explore other opportunities for growth. Delta Lloyd would be better positioned ahead of anticipated consolidation in the Netherlands and Belgium, it added.Originally, it was thought Aviva had planned the float for the new year, but the surge in stock markets recently and a high level of interest among Dutch investors encouraged it to move the date forward.Delta Lloyd's book value last August was €4.1bn.Shares in Aviva advanced in early dealings, but are now 2.23% lower at 442.50p.