Spain, the eurozone's fourth-biggest economy, borrowed more than seven billion euros ($9.0 billion) in two separate sales of sovereign debt.

The Treasury sold 3.88 billion euros of three-, five- and nine-year bonds in a standard auction, the central bank said, while the government said private investors bought 3.27 billion euros in bonds due in 2017.

After months of speculation that it would seek eurozone funds to trigger support from the European Central Bank, Madrid completed its 2012 borrowing target this month, all but warding off such a bailout this year.

Thursday's issuing of sovereign bonds saw Spain embark on borrowing to finance its activities in 2013, giving it a head start for next year as it battles to stabilise its public finances.

Spain was able to borrow more cheaply than before and demand on the market for the three- to nine-year bonds exceeded the Treasury's target, in a sign of easing tension over Spain's financial strength.

The rate of return fell to 3.617 percent from 3.66 in the last comparable sale of three-year bonds, to 4.477 percent from 4.766 on five-year bonds and to 5.517 from 5.545 percent on nine-year ones.

Economists have warned that Spain may yet need to be rescued in 2013 as it remains in a precarious state, in a long recession with one in four workers unemployed.

Another key measure of market concern, the difference between the rate charged on Spanish 10-year bonds and on those of safe-haven Germany, remained high on Thursday at 422 basis points.