The Fed said its holdings of U.S. securities kept for overseas central banks rose $6.26 billion in the week ended September 5, to stand at $3.574 trillion.

The breakdown of custody holdings showed overseas central banks ' holdings of Treasury debt rose by $۶.۸۴ billion to stand at $۲.۸۷۳ trillion.

Foreign institutions ' holdings of securities issued or guaranteed by the biggest U. S. mortgage financing agencies, including Fannie Mae(FNMA. OB) and Freddie Mac(FMCC. OB), fell by $۵۷۹ million to stand at $۷۰۰.۴ billion.

Overseas central banks, particularly those in Asia, have been huge buyers of U.S. debt in recent years and own more than a quarter of marketable Treasuries. China and Japan are the biggest two foreign holders of Treasuries.