The just-released Statistics of Income Bulletin (Fall 2004) includes Corporate Foreign Tax Credit, 2000 by Scott Luttrell (SOI).  Here is the summary:

For Tax Year 2000, 5,917 U.S. corporations claimed foreign tax credits, reducing their U.S. income tax liability by $48.4 billion.

For related data, see here.  For other corporate foreign tax credit data, see here.