Portuguese authorities managed Friday to ease wider market fears over the health of the country's biggest listed bank Banco Espirito Santo, which is being hammered by its parent group's debt woes.
"There is no reason to doubt the security of the funds entrusted to the BES, and its savers have no need to be worried," Portugal's central bank said in a statement.
Prime Minister Pedro Passos Coelho added: "There is no reason for the state to intervene in a bank which has solid capital and which has a comfortable margin to deal with any eventuality, even the most adverse."
Lisbon stock market regulators had suspended trading in BES shares on Thursday after they plunged by more than 17 percent.
But the ban was lifted around midday on Friday, and BES shares struggled to advance before throwing in the towel and ending the day with a further loss of 5.5 percent at 0.48 euros.
The overall Portuguese market was 0.62 percent higher, after losing 4.18 percent on Thursday.
Concerns that the bank's troubles could have a wider impact on Portugal -- which only two months ago exited a three-year, 77 billion euro ($106 billion) international bailout -- had rocked global markets as questions resurfaced over eurozone debt.
- BES exposure to holding company -
The Portuguese bank has been hit by suspicion that its holding company, the family-run Espirito Santo International (ESI), covered up a 1.3-billion-euro hole in its accounts.
BES said Friday that its exposure to debt in the Espirito Santo group reached 1.18 billion euros at the end of June.
However it did not have an estimate for potential losses related to the exposure, pending the publication of a restructuring plan from the group.
Moody's Investor's Service and Standard & Poor's cut BES's debt rating on Friday and kept it on a negative watch for possible further downgrades.
But financial markets in general took a broader look at the situation, and European stock markets ended the day with slight gains.
"Although there are still widespread concerns, bond markets are also reflecting the receding panic of earlier this week," ETX Capital analyst Daniel Sugarman noted.
The interest rate on benchmark 10-year Portuguese bonds stood at 3.866 percent on markets that trade government debt late Friday, compared with 3.985 percent on Thursday.
Spain's comparable rate eased to 2.771 percent from 2.825 percent, while that of Italy dropped to 2.888 percent from 2.945 percent.
Nordine Naam, a strategist at the financial group Natixis, remarked that "the Bank of Portugal... has reassured the market and calmed the situation".
In Brussels, the European commission said it stood by the Portuguese Central Bank statement and believed the crisis could remain limited.
"We are confident that any problem in the system will be managed in a timely and efficient manner," said Simon O'Connor, spokesman for the Economic Affairs commission.
The IMF, which managed Portugal's bailout with the EU, said late Thursday that "pockets of vulnerability" remained in the banking system, but noted that Portuguese lenders had "been able to endure the crisis without significant disruption".