Long-dated European government bonds extended their losing streak on Monday, sliding to levels not seen in nearly two decades as persistent worries over government finances kept pressure on the market. The 30-year segment of the curve bore the brunt of the sell-off, with yields climbing across the region.

France's 30-year yield rose as much as 2 basis points to 4.86%, its highest since September 2008. Germany's equivalent maturity gained roughly 2 basis points to 3.75%, reaching a level not observed since 2011. The UK's long bond also weakened, with the 30-year yield up 3 basis points at 5.82%, the highest since May 18.

Short-dated yields were largely unchanged, while the move higher at the long end pushed global yield curves into a bear steepening pattern. The divergence between the front and back ends highlighted the market's growing focus on sovereign debt sustainability.

In other moves, Germany's 10-year yield edged up 1 basis point to 3.22%, while Bund futures slipped 15 ticks to 124.25. Italy's 10-year yield rose 2 basis points to 4.00%, with the spread over German peers widening 1 basis point to 79 basis points. France's 10-year yield added 1 basis point to 4.05%, and the UK's 10-year yield climbed 2 basis points to 5.04%.