Jefferies analyst Ken Usdin reiterated a buy rating on State Street Corp. on Wednesday and said the retention of 15% of BlackRock Inc.'s /zigman2/quotes/207946232/composite BLK -3.10% ETF servicing business will benefit the company. State Street revealed in filings earlier this year that it would lose a chunk of its ETF servicing business from BlackRock. BlackRock has now finalized its new structure with Citigroup Inc. /zigman2/quotes/207741460/composite C -1.85% handling 40% of the $2.3 trillion ETF business, JPMorgan Chase & Co. /zigman2/quotes/205971034/composite JPM -1.75% handling 30%; also Bank of New York Mellon Corp. /zigman2/quotes/200171276/composite BK -4.57% and State Street with 15% each. "We see this as a win for everyone, with the loss well-telegraphed for STT but the retention of 15% a positive, as are the new wins for the others in a fast-growing asset class," Usdin said. Usdin said Jefferies has already subtracted $150 million in revenue from its models, but the actual figure could be about $160 million given asset value growth. Shares of State Street fell 0.9% in morning trading.