"Oil and gas is one of the sectors facing pressure on a fundamental basis," said Brigitte Posch, head of emerging market corporate debt at Babson Capital Management.
Some smaller, private companies will inevitably have to restructure debt, she believes, but warns a bigger headache could stem from state-run, quasi-sovereign firms.
Posch notes quasi-sovereigns such as Brazil's Petrobras or Mexico's Pemex make up more than 80 percent of the bonds maturing in the sector over the next four years.
That can pose a spillover risk to governments, should they need to support these entities, she added.
Just over a quarter of outstanding hard-currency debt due over the next three years is from energy and materials firms, Baweja estimates. Financials account for almost a third.
While government support makes companies' debt safer for investors, it tends to transfer risk to the sovereign and raise in turn borrowing costs for all other firms, said Baweja, with financials looking particularly vulnerable.
UBS data shows Turkey's gross debt refinancing needs are the highest in emerging markets when compared with its hard currency reserves. Hungary, Indonesia, South Africa and Russia are not far behind.
Glass Half Full?
One consequence of the borrowing spree is that emerging market companies are increasingly plowing money raised from markets back into repaying maturing debt, the International Monetary Fund has warned.
That percentage has rocketed to almost 30 percent in 2014 from less than 5 percent in 2005, it said.