* Strike over rail reform bill to continue at weekend
* Unions opposed to rail bill, government says reform needed
* Sunday strike by airport staff will add to disruption (Recasts with Hollande, adds airport baggage strike, other developments)
PARIS, June 13 The French government called on Friday for a rapid end to one of the longest railway strikes in years but labour unions vowed to prolong industrial action that risks disrupting end-of-school exams for hundreds of thousands of students.
A separate strike by baggage handlers at Charles de Gaulle airport north of Paris looked set to compound disruption on Sunday, with Air France predicting delays but no cuts in flights on a day when 150,000 people travel via France's main air hub.
Workers at the SNCF train operator voted to continue their three-day stoppage over a rail reform bill due to go to parliament next week, annoying President Francois Hollande.
"This does not mean the dialogue cannot continue but the time has come and this industrial action must come to an end," Hollande said.
Rail services have been cut or scrapped since the strike began on Tuesday evening over government plans to bring the SNCF rail operator and the RFF network company under the roof of one holding company while keeping their operations separate.
The unions fear the reform will harm work conditions and are campaigning for a return to a pre-1997 structure where the SNCF was a single entity. They also want the government to take on 40 billion euros ($54.5 billion) in debt owed by the two firms.
The unions say news last month of a mistaken order of hundreds of new trains that are too wide to enter stations provides proof of the dangers of deregulation.
Prime Minister Manuel Valls defended the reform, which the government says is needed to create a coherent structure for the railways as France and other European countries gear up for full-scale liberalisation of the railways in coming years.
Valls said he was "calmly but firmly" urging unions to call off their protest.
But the hardline CGT and Sud unions stood firm, despite news that other less militant unions were backing out after talks with Transport Minister Frederic Cuvillier.
The government's education department was working on ways to accommodate school children arriving late for the high-pressure "Baccalaureat" exams that mark the exit from secondary school, said Cuvillier. The exams start next week.
Striking a defiant note over the unions, he told France Info state radio: "In France it's parliament that makes legislation."
The SNCF rail operator said Eurostar links with Britain and Thalys links with Belgium and further north were expected to run normally, but other international links with countries such as Italy and Spain were still reduced, along with internal high-speed TGV train services, down as much as 50 percent on Friday.
Unions announced on Friday that the strike, renewable every 24 hours, would continue into the weekend. While the level of service disruption remains high, the SNCF company said the number of strikers had fallen to about 17 percent on Friday from more than 25 percent earlier in the week. (Reporting by Yves Clarisse, Leigh Thomas and Julien Ponthus; Writing by Brian Love; Editing by Gareth Jones)