Jan. 6 (Bloomberg) -- U.S. companies pulled away from stock repurchases last year at an even faster rate than share prices dropped, according to figures compiled by Birinyi Associates.

The amount of money that boards authorized companies to spend on their shares sank 58 percent from 2007’s total, Rob Leiphart, a Birinyi analyst, wrote in a report today. Actual repurchases tumbled 57 percent. By comparison, the Dow Jones Wilshire 5000 Composite Index fell 39 percent.

The CHART OF THE DAY shows the dollar amount of buybacks announced and completed annually since 1985, the starting point for the data from Birinyi, a research and money-management firm. Both appear in the top panel. The bottom panel displays the ratio between them.

The drop in proposed buybacks would have been even steeper if not for a $40 billion, five-year program that Microsoft Corp. started in September. Three more computer-related companies -- International Business Machines Corp., Hewlett-Packard Co. and Oracle Corp. -- combined for another $31 billion.

Authorizations at technology companies in the Standard & Poor’s 500 Index fell just 0.8 percent, to $101 billion. They plummeted more than 50 percent for the rest of the index’s 10 main industry groups.

U.S. companies approved $359.2 billion in repurchases and completed $330.4 billion worth last year. This equals about $1.09 of authorizations for every dollar spent -- the lowest ratio since 1991, the last time it was less than 1-to-1. The decline underscored the reluctance of companies to buy back shares.

To contact the reporter on this story: David Wilson in New York at dwilson@bloomberg.net

Last Updated: January 6, 2009 11:45 EST