Ludogorets, who are keen to reach the group stages in the European competitions for a fifth time since 2013, said Dimitrov had left the club following "gentlemen's conversations that ended at midnight".
A source close to the matter told Reuters on Tuesday that much-travelled Autuori had agreed to join the Razgrad-based side, who continued their domestic dominance by winning their seventh successive league title in April.
The 61-year-old Autuori guided Cruzeiro and Sao Paulo to Copa Libertadores titles and has also managed other top Brazilian clubs including Santos, Flamengo, Botafogo and Atletico Mineiro.
"(We turned to Autuori because) we want to continue the club's steady progress," Ludogorets' managing director Angel Petrichev said. "Our goal is to compete with teams, who are above the average European level.
"We currently have a modern Boeing but it is extremely important who will manage it."
One of the highlights of Autuori's club career came in 2005 when he led Sao Paulo to a Club World Cup triumph in Japan after a 1-0 win over Liverpool in the final.
The former Peru and Qatar coach has also been in charge of several Portuguese clubs, including Benfica as well as Qatari side Al-Rayyan, helping them to two Emir's Cup victories.
"I think that a specialist of such rank has not worked in Bulgaria until now," Petrichev said, adding that everyone at the club respected Autuori's career history.
Romania defender Dragos Grigore and Lokomotiv Plovdiv winger Dimo Bakalov have already signed for Ludogorets as they bid to strengthen their squad ahead of the Champions League qualifying phase.
Fitness coach Ivan Diaz has also joined The Eagles from Atletico Madrid.
Ludogorets have won 11 domestic trophies, including two Bulgarian Cups and two Supercups, since 2011 when they were promoted to the top-flight for the first time.
(Reporting by Angel Krasimirov; Editing by Christian Radnedge)
