Growing fears that a Greek default could infect heavily exposed French banks were heightened by concerns the banks could be hit by a Moody's credit downgrade.

Benchmark 10-year notes traded 7/32 higher in price to yield 1.894 percent, down from a close on Friday of 1.92 percent.

In very early trading, 10-year yields hit 1.878 percent, another low point not seen in at least 60 years.

The Treasury will sell $32 billion of three-year notes, $21 billion of reopened 10-year notes and $13 billion of reopened 30-year bonds this week. The three-year auction is set for Monday at 1 p.m. EDT. (1700 GMT)

Thirty-year Treasury bonds traded 22/32 higher in price to yield 3.22 percent, down from 3.25 percent late Friday.

Copyright Reuters, 2011