The mission chiefs of the four creditor institutions will arrive in Athens Wednesday to begin discussions on a third bailout package worth up to €86 billion over three years.
The European Commission's will be represented by Declan Costello, the European Central Bank by Rasmus Rueffer, the European Stability Mechanism by Nicola Giammarioli and the International Monetary Fund by Delia Velculescu.
Talks on a technical level began on Monday and were expected to be wrapped up by Friday, an official said, adding there could be "follow up" discussions over the weekend under exceptional circumstances.
"Both sides aim to reach a deal as soon as possible," the official said to Reuters.
If a bailout program can't be completed in time, Greece would need interim financing from a European Union emergency fund or another source.
Before talks on substantive policy issues have even begun, Greece and its creditors had a very public row of where to host the delegation of international auditors.
Greek authorities had insisted negotiators no longer use the Athens Hilton as their base instead proposing seaside hotels located in coastal suburbs far from the capital's government quarter.
But senior officials from Greece's bailout monitors have rejected the offer insisting that auditors should stay at the Athens Hilton, a hotel close to central Syntagma Square and a short drive to the finance ministry.
Another point of contention has been whether the foreign technocrats will be able to enter Greek ministries and negotiate directly with ministers, a procedure that Greece's coalition government, led by the radical left Syriza party, has rejected as a threat to Greece's sovereignty.
After assuming office, Greek Prime Minister Alexis Tsipras declared that the unpopular "troika" was finished, and refused to let international monitors into Greek ministry buildings, insisting instead on discreet meetings in Athens hotels, and talks in Brussels.
Nevertheless Tsipras's radical left government had to accept the inspectors' return to Athens after the Greek parliament voted for a two sets of tough new conditions set by the EU lenders for talks on the bailout.
While the Greek government and its creditors have agreed to let inspectors enter ministry buildings and institutions such as the Bank of Greece and the General Accounting Office, it remains unclear how much access they will have to several key ministers.
At the same time sticking points remain with the creditors demanding a third package of "prior measures" to be voted in Parliament, including tax hikes, pension cuts and introducing a single pay scale for civil servants before negotiations conclude.
Athens argues it has already taken the short-term measures it promised under the political deal on a new bailout reached with European leaders on July 12. However, Mr. Tsipras's omitted a measure that would end decades-old tax breaks enjoyed by farmers.
Besides tax hikes on farmers, changes in early retirement which have been the stickiest point in the negotiations, have not been included in last week's package.
In terms of pensions, Greece's creditors demand reforms to create strong disincentives to early retirement (including changes to early retirement penalties), gradually phase out the solidarity grant (EKAS) for all pensioners by end-December 2019, and increase the health contributions for pensioners from 4% to 6% on average and extend it to supplementary pensions.
In the longer term the government must also raise €50 billion from privatizations and undertake market reforms including liberalization of Sunday trading and deregulation of its dairy, bakery and pharmacy sectors.