BRUSSELS - Greece must implement the reforms it agreed to under the second bailout programme and the European Commission is ready to help Athens with that, the European Union executive said on Monday, after Greek parties opposing the bailout did well in elections.

"Full and timely implementation of the programme is of the essence in order to meet the targets and (reach) sustainability of the Greek debt," Commission economic and monetary affairs spokesman Amadeu Altafaj told a regular news briefing.

Greece's conservative leader, whose New Democracy party won the biggest support in elections on Sunday, began a hunt for partners to forge a coalition that would continue reforms agreed with the euro zone and the International Monetary Fund, which are a condition for continued emergency financing for Athens.

Without the EU/IMF funds, Greece would have to default on its debt, which some politicians believe would entail leaving the euro zone and the European Union.

But on Sunday, voters savaged the two ruling parties for imposing steep wage and spending cuts, in line with the bailout terms, and forming a coalition government in support of the reforms might be difficult.

"A second programme has been negotiated with the Greek authorities, on behalf of the Greek state... the private sector has contributed... but of course when it comes to implementation, it is up to the Greek authorities," Altafaj said.

The bailout programme is an ambitious deal struck in February that aims to clear the way for Greece to return to financial markets by 2015.

"We stand ready to continue to assist Greece with its ongoing reform agenda in the framework of the second economic adjustment programme," European Commission spokeswoman Pia Ahrenkilde Hansen told the briefing.

The Commission said it was premature to anticipate what decisions a future Greek government that might emerge from the coalition talks could take regarding the bailout reforms.

"We do not have a new government in Greece yet," she said. "The Commission hopes and expects that the future government of Greece will respect the engagement that Greece has entered into."

Greece consistently missed targets under its first programme, agreed in April 2010, which led to the restructuring of its private-sector debt under the second package.

Officials say any further backsliding now will not be tolerated, especially with the International Monetary Fund a reluctant partner in the second programme.