Greece will proceed with the privatization of the country’s main port of Piraeus, Greek Finance Minister Yanis Varoufakis plans to tell his eurozone counterparts at a meeting in Brussels on Wednesday, backtracking on previous statements from the new leftist government that had pledged to freeze the deal, senior Greek government officials said.

The U-turn comes as Greece’s new leftist, Syriza-led coalition government scrambles to reach a financing deal with international creditors that will keep the country from running out of cash in coming weeks and potentially defaulting on its debts. Since being voted into power just over two weeks ago, the new government has set a collision course with its European creditors by promising to roll back many of the austerity measures and reforms--such as privatizations--that Greece has undertaken in the past five years to secure billions of euros in aid.

Selling the state’s 67% stake in the Piraeus Port Authority is one of the biggest divestments of an ambitious privatization plan agreed to by the previous conservative government with the so-called troika of creditors--the European Union, the European Central Bank and the International Monetary Fund--for the debt-ridden country to continue receiving bailout funds. It is also one of the more symbolic: The port of Piraeus, just a few miles south of the Greek capital of Athens, is the de facto home of Greece’s giant shipping industry and is one of the largest ports in the Mediterranean.

“The Piraeus sale is on. It will proceed as planned,” a senior finance-ministry official told The Wall Street Journal.

People with knowledge of the deal said the port sale could yield up to EUR800 million ($908 million), and binding offers are expected by the end of March.

Greece had agreed with creditors that it would realize total privatization proceeds this year of around EUR2.8 billion--a figure Greece may struggle to reach. The full privatization plan was to include selling a variety of assets, including the operating concessions to 14 airports around the country, the natural-gas distribution network and some state-run hotels and property. The new government insists that some things won’t be sold, such as the state-owned national utility, but senior EU officials say the Piraeus sale is a key test case.

An expanded version of this report appears at WSJ.com.