More companies are having trouble keeping up with their interest payments , according to a new report from consulting firm Kearney. 

Industry parlance for these debt-burdened firms is "zombie companies," firms that have not been able to keep up with these payments for three years. There has been a 10 percent increase in their number since 2021. Now they account for just under 5 percent of all listed companies globally, which brings their total to nearly 2,000 zombies around the globe. 

Crucially for the broader economy, zombie companies are at a higher risk of insolvency, so in theory any sudden shift in the market could finish them off. 

"Over the past year, it's become clear that rising energy and raw material costs, strained supply chains and staff shortages are weighing on companies' revenues, with financing problems compounding the problem for many," said Nils Kuhlwein von Rathenow, partner at Kearney.

Only a few firms are actually shutting down due to insolvency, he added, in large part because easy credit conditions have kept them on life support. However, with the Federal Reserve raising interest rates, Kearney predicts the number of zombie companies could jump another 40 percent. 

The trend goes back to the years after the Great Recession. In North America, the share of zombie firms increased from 3.5 percent in 2010 to 5.7 percent in 2021. Over the same period in Europe, the number jumped from 1.2 percent to 5.5 percent. 

Some measures place the number significantly higher within the U.S. Goldman Sachs in 2022 said 13 percent of U.S.-listed companies were zombies (though it also argued that fears of their impact on the rest of the economy were overblown). 

Which companies specifically qualify as zombies? While exact definitions differ, some companies that pop up on multiple lists include Peloton, Rivian, and Beyond Meat, to name just a few. 

One entire industry that is becoming more zombified is real estate, according to Kearney.  The consulting firm found that 9 percent of real estate developers were zombies, and 11 percent of diversified real estate companies. 

"A particularly worrying finding from our analysis is that one in seven listed companies in the global real estate sector is at risk of being classified as a zombie company, ominously mirroring the years before the financial crisis of 2008/2009," said Christian Feldmann, partner at Kearney. 

He added that a total of $500 billion in capital is being misallocated by zombie firms. 

"The figures are clear, we need action now," he said.