July 2 (Reuters) - Nikola said deliveries of its hydrogen-fuel cell trucks rose 80% in the second quarter from the previous three months, surpassing the startup's expectations and signaling strong demand for the big rigs amid its pivot from battery-powered vehicles.

Shares of the company rose nearly 4% in premarket trading on Tuesday. The stock has lost over 70% of its value so far this year.

The company delivered 72 Class 8 Nikola hydrogen fuel cell trucks to wholesalers in the quarter ended June 30, compared with 40 in the previous quarter, and above its sales forecast of between 50 and 60 trucks. (Reporting by Deborah Sophia in Bengaluru; Editing by Tasim Zahid)