A halt to international payments from Greek bank accounts is hurting Greek businesses and their foreign partners and threatening supplies of vital goods like food and clothing into the debt-crippled country.

With banks closed, people limited to withdrawing 60 euros ($66.62) per day and Greece's future in the euro possibly hinging on a referendum on Sunday, Greek shoppers have been stocking up on essentials like sugar, flour, pasta, rice, beans, canned and paper goods.

Shelves remain full for now as retailers have inventories in storage. But capital controls put in place after Greece defaulted on a loan to international creditors have essentially frozen companies' cash flows and credit.

This has severely hampered production and shipping, meaning that goods are in finite supply. With this week's rush to supermarkets, shortages could be around the corner although budget limits are providing some cushion.

"At this stage there is no problem of shortages. There is sufficient stock in our warehouses and we renew it frequently," said Melina Varoutsikou, spokeswoman for Sklavenitis, one of Greece's largest supermarket chains.

"However, nobody knows how much these can last. It all depends on which product we are talking about."

With no international bank transfers, imports and exports have been clobbered, according to SEV-Hellenic Federation of Enterprises, meaning there are fewer raw materials, even for local production, and less petrol available for deliveries.

The Greek finance ministry said on Friday that companies wishing to process bank transfers abroad to pay suppliers must submit a request to the Committee of Approval of Bank Transfers through their commercial bank.

The ministry said companies can get further information by going to their home branch or calling their bank's central number. But for quicker processing, the ministry recommended faxing the requests. It made no mention of e-mail, the medium often used for international business.

Meanwhile, sellers of perishable items like fresh fruit and vegetables stand to realize losses as shipments are stalled.

"The food and beverage industry suffers heavily," said George Xirogiannis, director of industrial and sectoral policies for SEV, a trade group involved in lobbying the government to reconsider its position on cross-border transactions.

"Cash flow problems are spread throughout the economy, regardless of the size of the enterprise."

Large multinationals such as Nestle, Procter & Gamble, L'Oreal and Coca-Cola operate in Greece and could see a sales hit, since wholesalers that lack online banking facilities or international accounts have been unable to execute any payments abroad.

"Payment transactions have been severely affected," said an official from an international consumer goods company who spoke on condition of anonymity....