Solaria shares jumped 4.2 percent after the announcement and settled back to a gain of 2.4 percent at 19.14 euros by 1416 GMT.

Solaria said the contract, due for delivery this year and next, had already been detailed within its order book when the company presented nine-month results, but at the time DTL was only identified as "Client 2".

The company's shares have more than doubled in value since it listed in June amid a wave of excitement over renewable energy stocks. Iberdrola Renovables, the renewables unit of Spain's biggest utility is due to list Dec. 13.