Key longer-dated eurozone bond yields tumbled on Monday as attacks on Saudi Arabia's crude facilities and weak numbers from China supported interest for risk-off assets.
Bond yields are slipping again following hitting six-week peaks a week ago, as uncertainty was thrown on the effect new upgrade estimates reported by the ECB could have on the euro zone's slothful economy.
Oil flooded to four-month peaks on Monday after the end of the week attacks on crude offices in Saudi Arabia started supply fears, closing 5 percent of world output.
Most longer-dated core eurozone government bond yields were down 1 to 2 bps.
Germany's 10-year benchmark slipped 1 bp at -0.46 percent. Bund futures rose 22 ticks toward the beginning of the exchange.
Meantime, Portugal's 10-year bond is failing to meet expectations, with the yield up 2 basis points after S&P raised the attitude toward the sovereign's BBB rating to positive on Friday.
The gap among Portugal and better-appraised Spain's 10-year bond yields touched a record low of -5 bps a week ago.
Attention will stay on the ECB on Monday, with policymakers Francois Villeroy de Galhau, Philip Lane and Sabine Lautenschlaeger all due to talk.