S. economy will translate into more green in the bank. Alternative-energy projects have been scaled back in recent months as oil prices have dropped and developers have struggled to secure financing.

Several countries, including China and India, continue to subsidize consumer fuel costs and in some cases have cut gas-station prices this year as oil prices have surged.

Although both airlines made hefty losses last year, the improving economy, recovering business traffic and cheaper fuel created the conditions for a second attempt.