WASHINGTON  Despite a recession that knocked down global arms sales last year, the United States expanded its role as the world’s leading weapons supplier, increasing its share to more than two-thirds of all foreign armaments deals, according to a new Congressional study.

The United States signed weapons agreements valued at $37.8 billion in 2008, or 68.4 percent of all business in the global arms bazaar, up significantly from American sales of $25.4 billion the year before.

Italy was a distant second, with $3.7 billion in worldwide weapons sales in 2008, while Russia was third with $3.5 billion in arms sales last year  down considerably from the $10.8 billion in weapons deals signed by Moscow in 2007.

The growth in weapons sales by the United States last year was particularly noticeable against worldwide trends. The value of global arms sales in 2008 was $55.2 billion, a drop of 7.6 percent from 2007 and the lowest total for international weapons agreements since 2005.