Portugal has become the third country in the eurozone to request financial aid in the form of a cash bailout from the European Union.
Greece and Ireland have already asked for help, the BBC reports.
Portugal's Prime Minister, Jose Socrates, says the bailout is a last resort but the country is at too much risk.
Mr Socrates did not say how much aid Portugal would ask for but a euro zone official estimates Portugal is likely to need between 60 million and 80 billion euros in European and International Monetary Fund loans over three years.
Earlier, the government raised about 1bn euros after tapping the financial markets in order to repay loans, but will have to pay a higher interest rate to lenders.
In a statement, European Commission President Jose Manuel Barroso said the request would be processed as swiftly as possible and reaffirmed his confidence in Portugal's capacity to overcome its difficulties.
Portugal's cost of borrowing has risen sharply since the minority Socialist government resigned last month after its proposed tougher austerity measures were defeated in parliament, the BBC says.
Greece received a 110 billion euro package, while Ireland's package is worth 85 billion euros.
