Services on the Berlin-Stuttgart line would resume on August 24th, Flixbus said in a statement, adding that tickets could be booked through the Flixbus network.
As part of the rescue deal for insolvent Locomore, the Czech transport firm Leo Express will take over rail operations.
"We are convinced that through the Flixbus network we can attract the passenger numbers needed to ensure a sustainable operation of the Locomore routes even at low ticket prices," Flixbus managing director Andre Schwaemmlein said in the statement.
Locomore, which billed itself as the world's first crowd-funded train service, launched to great fanfare last December after attracting some €600,000 in start-up capital from online supporters.
Hoping to challenge the might of Deutsche Bahn, it began running a daily return service from Stuttgart to Berlin that passed through Frankfurt and Hanover, at lower prices than those of the German state rail operator.
But bookings were slow and, after struggling with high maintenance costs, Locomore filed for insolvency in May.
To mark the resumption of Locomore's services, Flixbus said it was offering long-distance train tickets from €9.90 while charging five euros for shorter stretches.
Passengers who had contributed to the crowd-funding effort would receive free tickets, Flixbus said.
Before it went into administration, Locomore said its refurbished 1970s train, which retained a retro look with its brown-and-orange livery, had transported some 70,000 passengers.
Germany's rail sector was liberalised in 1994 but remains dominated by Deutsche Bahn, which carries more than 5.5 million passengers a day and accounts for 99 percent of all long-distance rail journeys.
The Locomore rescue is not the first time Flixbus and Leo Express have teamed up.
The two firms have been linking up their bus and rail services in the Czech Republic since 2015, according to the statement.