Airlines pulled back from bidding in the European Union’s auction for permits covering greenhouse gas pollution, another indication that demand for energy is dropping rapidly.

None of the four bidders for carbon emissions allowances were successful in a contest for airline carbon allowances run by ICE Futures Europe on Wednesday. It was the second auction failure in a little more than a week.

With many flights grounded and carbon prices on the slide, demand for the securities is weakening. Thousands of industrial sites, power generators and airlines are required to buy the credits for their greenhouse-gas pollution. But with the economy and energy use weakening, their need for those permits is declining too.

Airline carbon contracts are earmarked for that industry and trade infrequently compared with the allowances used by factories and electricity generators. That makes them less attractive for speculators.

“There’s a lack of readily available capital in situations like we’re experiencing” because of the pandemic, said Louis Redshaw, founder of the carbon trading outfit Redshaw Advisors Ltd. “No one wants to hold on to EU aviation allowances as they can’t be readily sold back to realize the capital if it’s needed quickly.”

The auction failed because there weren’t enough bids to cover the supply being offered, ICE said. Airlines have been some of the hardest hit businesses during the coronavirus crisis, with Ryanair Holdings Plc, Lufthansa AG and British Airways canceling flights as restrictions related to the health crisis spread.

The contest on Wednesday was further complicated by the expiry of March options and by the scale of another auction held earlier in the day.

Poland auctioned 5.3 million tons of allowances on the European Energy Exchange on Wednesday morning, and demand barely exceeded supply. Together, the permits on sale in the two auctions on Wednesday were more than double the normal daily size of 3.1 million tons.

The current price of carbon is about a quarter lower than it was two weeks ago, and there’s little indication of a demand boost while much of Europe’s economy remains on standby.

An auction on March 17 was canceled because the total volume of bids fell short of the volume of available contracts. That was the first failure since June.

“Seeing a bloodbath on the market as we’ve seen the past few days, makes it difficult to assume the point that people get back in with large volumes,” Marcus Ferdinand, head of European power and carbon analytics at research company ICIS, said in a phone interview before the latest result.

Profits from burning coal for power remain low or non existent, suggesting utilities probably won’t be big buyers.