Standard & Poor's said on Tuesday that BlackRock Inc. will replace Genzyme Corp. in the S&P 500 index after the close of trading on Friday.
New York-based BlackRock is the world's largest asset manager. Its shares rose $8.90, or nearly 5 percent, to $195.40 in after-hours trading after the news was released. Stocks that are added to major indices typically rally, because it's expected that mutual funds and other investment vehicles that track the index will buy shares.
S&P is making the change because biotech company Genzyme agreed last month to be taken private for $20.1 billion by France's Sanofi-Aventis SA.
In January, BlackRock reported that its profit more than doubled in the last three months of 2010 to beat Wall Street estimates as it attracted new business and saw money management fees rise. BlackRock has benefited from the 2009 purchase of Barclays Global Investors. The company's iShares exchange-trade business, part of Barclays, drew a net $13.4 billion in investor cash in the fourth quarter.