Interest rates fell in the bond market Monday after the euro tumbled to another four-year low on persistent worries about Europe's ability to manage heavy debt loads.

The demand for Treasurys drove rates lower. The yield on the 10-year note, which is tied to rates on mortgages and other consumer loans, fell to 3.15 percent from 3.21 percent late Friday.

The price on the note maturing in May 2020 rose 50 cents to $102.96875.

Rates fell after the euro traded below $1.19, the lowest level since March 2006. The currency has touched a series of four-year lows in recent days on worries about Europe's growth prospects and the effects of government spending cuts.

Hungary became the latest European Union country to stir concerns when its new government warned last week that the country's economy is in dire shape. The country, which isn't part of the 16-nation block that uses the euro, tried to downplay those concerns Monday.

Treasury prices had skyrocketed in recent days because of worries about Europe's debt situation, sending yields in the 10-year and 30-year bonds to their lowest levels of 2010.

The fear is that weakness in smaller European countries could lead to more expensive bailouts, as happened with Greece. European countries and the International Monetary Fund have agreed to a $1 trillion emergency loan package to shore up weak countries, but investors are not yet convinced that that will be enough to prevent the crisis in confidence in European government debt from deepening.

In other trading, the yield on the 30-year Treasury bond maturing in May 2040 fell to 4.08 percent from 4.13 percent. Its price rose 93.75 cents to $105.0625.

The yield on the two-year note that matures in May 2012 rose to 0.75 percent from 0.73 percent. The price fell 3.125 cents to $100.03125.

The yield on the three-month Treasury bill maturing on Sept. 2 fell to 0.11 percent from 0.12 percent.