The head of Portugal's debt agency says a 990 million euro ($1.34 billion) bond auction was oversubscribed, suggesting the government's austerity plan has eased market concerns about the country's high debts.

Debt agency president Alberto Soares told The Associated Press the institution received bids worth 1.58 billion euros ($2.15 billion) for the April, 2021 bonds at a rate of 4.17 percent Wednesday.

"It went very well," Soares told the Associated Press.

The auction came two days after the minority Socialist government unveiled the broad outline of a four-year austerity plan.

The package of measures is designed to allay fears Portugal could face similar problems to Greece where a budget crisis has triggered violent demonstrations and unsettled the European Union.