Last week's volcanic ash cloud cost European Union airlines 1.5-2.5 billion euros ($2-3.3 billion), the EU executive said as it proposed a series of actions to help the cash-strapped industry. Governments will be able to waive restrictions on night flights and defer charges paid to air traffic controllers to help airlines cope with cash-flow problems, Reuters quoted the European Union's transport chief as saying on Tuesday. "We have taken all assessments and valuations of costs from all the different stakeholders and we are working with a number between 1.5 and 2.5 billion euros," European Transport Commissioner Siim Kallas told a news briefing. The estimate covers all sectors of the aviation industry, including airlines, airports, tour operators and ground handlers, hit by the cancellation of around 100,000 flights which left about 10 million travellers stranded around Europe. As an economist, Kallas said he would treat industry estimates with scepticism as he tried to ascertain the final bill. "Member states should be able to provide temporary derogations from scheduling restrictions -- such as night flying restrictions -- to bring stranded passengers home as quickly as possible and get freight deliveries back to normal," said Kallas. "Temporary measures could also be foreseen to help airlines with short-term cash flow problems, by deferring for a limited period the en-route charges normally paid by airlines to air traffic control," he added.