CREATE TABLE table_21115 ("Company" TEXT, "ICB Sector" TEXT, "Ticker symbol" TEXT, "Index weighting  ( % )  at 17 January 2013" TEXT, "Market cap. at April 2013  ( \\u20ac ) " TEXT)

Name the icb sector for ai
SELECT "ICB Sector" FROM table_21115 WHERE "Ticker symbol" = 'AI'
SELECT "ICB Sector" FROM "table_21115" WHERE "Ticker symbol" = 'AI'