The 10-year German bond yield was up 1.1 basis points at 3.096 percent, while the two-year yield rose 0.5 bps to 1.47 percent.

Overnight, US Treasuries remained well-supported by safe-haven flows as Japan's battle to avert a nuclear crisis kept investors on edge, though European equities were set to edge higher after recent heavy losses. "Markets are going to remain very skittish while no-one really knows what is going on (in Japan).

Supply is going to interfere with things a little but data is taking a back seat and Japan is really the only story in town," a trader said.

In the euro zone, the latest test of investor appetite for lower-rated government debt comes as Spain sells up to 4.5 billion euros of 2021 and 2041 bonds.

In the face of broad risk aversion in global markets, the Spanish yield spread over Bunds remains tighter after making gains on Monday following the weekend's unexpected progress by EU leaders on strengthening the euro zone bailout fund. "Despite the lack of concession, we feel the auctions should be supported by the better market sentiment seen post the announcements for a euro area stability pact at the weekend," said Barclays Capital analysts in a note.

Market participants noted that with the high volatility seen in core markets this week, trading in peripheral debt had become increasingly light.

France also sells up to 8.5 billion euros of shorter-dated conventional bonds along with inflation-linked debt.