By Will Andrews

Here are the top 25 companies for stock repurchases, and how their shares have fared, since the fourth quarter of 2004

According to a report prepared by Standard & Poor's senior index analyst Howard Silverblatt, companies in the S&P 500 index were expected to have made $87.9 billion in stock repurchases during the 2008 second quarter, a 44.3% decline over the $157.8 billion spent during the second quarter of 2007. Since the buyback boom began during the fourth quarter of 2004, S&P 500 companies have spent approximately $1.64 trillion on stock buybacks, compared to $1.73 trillion on capital expenditures and $845 billion on dividends, according to Silverblatt.

Who has been buying the most stock during that time? And how have the stock prices of the big repurchasers fared over that period? Here's a look at the top 25, based on repurchase data provided by S&P Index Services and pricing info from CapitalIQ (S&P and CapitalIQ, like BusinessWeek, are units of The McGraw-Hill Companies).