(Adds U.S. Treasury purchasing data)
NEW YORK May 15 (Reuters) - Foreign capital inflow into U.S. Treasuries declined in March after strong numbers the previous month, but support for this asset class came mainly from an unconventional buyer -- Belgium.
Holdings of U.S. Treasuries in Belgium rose a net $40.2 billion in the month. Over the last five months, Belgium's buying totaled about $201.1 billion.
This euro zone country is now the third largest holder of U.S. Treasuries with $381.4 billion, after China and Japan.
"This is consistent with the recent trends and continues to suggest another country is running their purchases through a Belgium-based custodian," said Ian Lyngen, senior government bond strategist, at CRT Capital in Stamford, Connecticut.
Overall, Treasuries posted net inflows of $25.9 billion two months ago, from $92.5 billion in February.
In total, foreigners bought $4 billion in long-term U.S. financial assets in March, compared with revised inflows of $90.3 billion the previous month.
Including short-dated assets such as bills, overseas investors sold $126.1 billion in March, reversing inflows of $175.9 billion in February. (Reporting by Gertrude Chavez-Dreyfuss, Editing by W Simon)