Production at the Elephant field boosted Libya's oil output from around 150,000 barrels per day to nearly 300,000 bpd.
Maritime traffic data from the Platts energy news service show Scorpio, a Greek-flagged crude oil tanker, left the Libyan port of Mellitah last weekend headed toward the Italian port city of Trieste.
Platts reported Monday that it marks the first delivery from Libya's Elephant field since operations began June 16.
Libyan rebels vying for more autonomy seized oil export terminals last year. The ripple effect pushed oil production down from the pre-civil war peak of around 1.4 million bpd to below 200,000 bpd.
Libya relies on oil for 96 percent of its gross domestic product. The Libyan government this week said it expected to run an $8 billion deficit this year. It passed a budget based on a production level of 800,000 bpd and oil priced at $100 per barrel, about $14 less than the price Tuesday for the global benchmark, Brent.