The fight for an increased global share of the exchange-traded fund market is intensifying as US giants iShares, State Street and Vanguard have moved to tighten their grip on the sector.

They already control 71% of global ETF assets totalling $1.53 trillion, according to data from ETFGI. Their fresh assault has forced restructurings at Societe Generale's Lyxor, Credit Suisse and HSBC to enable them to fight back from their European heartland. Changes are pending at Deutsche.