Ireland's financial troubles are looming large as investors drive the interest rate on the country's 10-year borrowing to a new high.

The yield on 10-year bonds rose above 8 percent for the first time since the Irish debt crisis began.

The yield, or interest rate, rose steadily to reach 8.16 percent by midmorning, with rates rising as bond prices fall.

Bond traders increasingly believe that Ireland soon will be forced to tap Europe's emergency fund for euro-zone nations facing potential bankruptcy.

Prime Minister Brian Cowen insists Ireland has enough cash on hand to fund the government budget through June 2011.

But he needs the interest rates being demanded by investors to fall substantially before Ireland needs to borrow again in early 2011.