The three-week shutdown of Greek banks has cost the country’s struggling economy some 3.0 billion euros ($A4.41 billion) not counting lost tourism revenue, a report says.

Citing commerce groups, the Kathimerini daily on Saturday said the retail trade alone had suffered a 600-million-euro loss, with apparel taking the main blow.

Exports also suffered a 240-million-euro hit, the exporters’ association said.

• Merkel backed on Greece bailout
• It’s over: Greece strikes deal with creditors
• Greek PM stares down bailout opponents
• Greece passes austerity plan

According to the Athens Chamber of Commerce and Industry (EBEA) some 4500 containers with raw materials and finished products are blocked at customs.

And with a significant backlog of cheques and bills of exchange that cannot be paid, business transactions worth an estimated 6 billion euros have been frozen, the chamber added.

The bank closure was enacted on June 29, after the radical Greek government rejected austerity demands by its international creditors and called a referendum on the issue that the nation backed by over 61 per cent.

But with the creditors threatening Greece with a eurozone exit, the government was faced with total economic paralysis and had to accept a package of tough fiscal reforms last week.

The bank restrictions did not affect foreign card holders, but the crisis also depressed new bookings at the height of the busy tourist season.

Because of the disruption, the government offered Athens commuters free passage on the city’s public transport network for around two weeks – a measure expected to cost the state budget 10 million euros according to reports.

The European Central Bank on Thursday boosted its lifeline to Greek banks by 900 million euros, and eurozone nations agreed to crucial short-term funding.

In response, the Greek government announced that banks would reopen on Monday, although withdrawals would still be capped at 60 euros a day.