"A tanker carrying 80,000 metric tons of oil set off [from Libya] on Tuesday to deliver oil to Swiss consumers," association chief Rolf Hartl told Swiss media.
Also on Tuesday, Libya released on bail two Swiss nationals who were detained in an apparent tit-for-tat move after Muammar Qaddafi's son Hannibal was arrested in Geneva on July 15 over allegations that he assaulted two hotel employees.
The Swiss Foreign Ministry said the released Swiss nationals are currently at the country's embassy in Tripoli, and have not yet been given permission to leave Libya.
Libya halted oil shipments to the country and suspended the issuing of visas to Swiss nationals last week. Tripoli also recalled its diplomats from Switzerland and forced Swiss firms to close their Libyan branches.
Switzerland has sent a diplomatic delegation to Tripoli to provide Libyan authorities with detailed information over the arrest and to discuss the current situation.
Qaddafi, notorious for his misconduct, spent two days in custody, while his pregnant wife was under police supervision in a clinic in Geneva. They were released on bail and left Geneva.