More than 100 companies – including News Corp Australia, Amcor, Golden Circle and Visy – may lose clean technology grants worth more than $53m as the Abbott government searches for budget savings.

During the election campaign the Coalition pledged to save $400m by discontinuing the Labor government’s clean technology program, part of $42bn in savings it outlined to pay for its election pledges. The clean technology fund was paid for by the carbon price, which the Coalition will also seek to repeal as its first legislative act.

Ministers have now been asked to look for further savings – including reconsidering discretionary grants across all portfolios – as economic growth remains subdued and the new government prepares a mid-year budget review for release before Christmas.

Guardian Australia has learned there is not $400m of uncommitted money left in the clean technology fund the Coalition has promised to cut, forcing it to consider withdrawing formal offers of funding already made to leading companies for detailed projects to reduce their carbon emissions, if legally binding contracts have not yet been signed.

A spokeswoman for the industry minister, Ian Macfarlane, said the government would find the $400m.

“The savings target does not impact on companies that have signed funding agreements in place. The government is still considering arrangements for grants offers,” she said.

Projects for which formal offers had been made by the former Labor government, but contracts not signed, are understood to include two separate plans by News to reduce the energy costs of its printing presses, for which the company had been promised almost $1.3m towards total costs of more than $4m.

It is understood offers had been made to a total of 110 projects proposed by more than 100 firms, including Rheem Australia ($1.5m), Austral Bricks (three projects worth almost $14m), Boral Cement, Visy Packaging, Amcor Packaging, Arnotts Biscuits and the Kilcoy Pastoral Company, which had been promised a total of $3.6m to reduce methane emissions from its meat processing plant and carbon emissions from its refrigeration.

Other companies promised grants were Downer EDI, CSR Building Products, Holden, Electrolux, Buderim Ginger, Laminex, Pfizer and Goodman Fielder as well as many smaller bakeries and food and wine companies.

The $53m was set to co-fund projects worth a total of almost $169m. They would have abated 2,700 kilotonnes of carbon. Some of the companies planned to use the money to restructure their operations and close older plants, some to change lighting or electricity generation, some to improve insulation or cooling plants.

Without any tax liability after the carbon price is repealed, many of the companies may now abandon their plans if the funding is withdrawn.

Others could re-apply to the Coalition’s emissions reduction fund (ERF), which will offer a total of $300m to emissions-reducing projects in its first year of operation. It will begin making grants next July. The ERF has similar aims to the existing clean technology funds – offering companies the chance to compete for government grants to help reduce their emissions.

The government is set to release the terms of reference for its promised commission of audit – which will review all government spending and functions.