Merrill Christer Aggett, 32, was found guilty by Solna District Court on Thursday of two charges of serious assault, 13 charges of attempted assault, six charges of sexual exploitation of a minor, one minor narcotics offence and two charges of driving without a licence.
The trial is to be resumed next month after the court ruled that Aggett should now undergo a psychiatric analysis, which is scheduled for completion in mid-December.
If found to suffer from a psychiatric disorder, he will sentenced to secure psychiatric care rather than prison.
Aggett is believed to have contacted 130 girls between 2002 and 2006 via internet chat sites.
Two young girls were diagnosed as HIV positive after sleeping with Aggett. Prosecutors successfully argued that he should be convicted of serious assault for infecting the girls.
Aggett also faced charges of attempted assault for having unprotected sex with other young girls, none of whom were infected. Many of them were under 15 when they slept with him.
The British citizen, who has lived in Sweden since he was a child, was arrested in the early summer. Aggett himself was diagnosed as HIV positive in 1992.