The Bulgarians and a Palestinian physician have the right to appeal the sentences handed down Tuesday, court officials in Tripoli said.
The six pleaded innocent, and were originally sentenced to death by a firing squad in 2004, but in December 2005, the Tripoli court overturned the Benghazi court death sentences and ordered a retrial, which began in May.
Defense lawyers told the Tripoli Court of Appeals the six were sentenced based on false evidence.
The six people have been in Libyan prisons for the past seven years charged with infecting the children in 1999 in a Benghazi hospital with the HIV virus that could cause AIDS. Since then, 52 of the children have died of AIDS.
"We strongly condemn and reject the death sentences," Parvanov said. "The Libyan court once again dismissed the irrefutable proofs and covered up the real reasons for the outbreak of the HIV epidemics in Benghazi."
Newt Gingrich fires back at Mandela backlash
Puzzle-maker slips 'Murdoch Is Evil' into Rupert Murdoch's Sunday Telegraph