Foreign central banks' holdings of U.S. Treasuries at the Federal Reserve rose sharply in the latest week, data from the U.S. central bank showed on Thursday.

Treasuries held by overseas central banks at the Fed jumped 28.71 billion to total $2.129 trillion in the week to Oct. 21.

However, foreign central banks' holdings of securities issued or guaranteed by the two biggest U.S. mortgage financing agencies, Fannie Mae (FNM.P) and Freddie Mac (FRE.P), fell by $70 million to $764.30 billion in the same week.

The combined holdings of Treasuries and agency securities by foreign central banks at the Fed rose by $28.64 billion to total $2.893 trillion in the week.

Overseas central banks, particularly in Asia, have been huge buyers of U.S. debt in recent years and own more than a quarter of marketable Treasuries. China is the largest such buyer, followed by Japan.

The full Fed report can be found on:  (Reporting by Burton Frierson; Editing by James Dalgleish)