YANGON (REUTERS) - A Myanmar court has jailed two reporters for two months for defamation, a newspaper editor said on Thursday, in a case likely to raise concern about a reform programme after half a century of strict military rule.

The media in Myanmar has enjoyed sweeping freedoms since a semi-civilian government took power in 2011 but the Committee to Protect Journalists said recently that since then, 10 journalists had been jailed and 19 were facing trial, and Myanmar was the 10th worst jailor of media workers in 2014.

The Myanmar Post Journal said a court in Mon State had sentenced its chief editor, Than Htike Thu, and deputy chief reporter, Hsan Moe Tun, to the prison terms on Wednesday after a military representative to parliament had filed a complaint.

Thaw Naing, the newspaper's editor-in-charge, told Reuters the military representative had complained he was misquoted in a report about the sharing of seats in parliament between civilians and military representatives.

The role of the military in parliament is sensitive with the party of opposition leader Aung San Suu Kyi calling for constitutional changes that would essentially weaken the military's legislative powers.

Thaw Naing said his journal stood by its report. "We'll open all legal avenues for the freedom of our men,"he said.

Veteran journalist and patron of the Myanmar Journalists Association Pho Thaukya said he was dismayed by what he regarded as unusually harsh punishment for the reporters. "It's completely unacceptable at a time when the country is building democracy," he said.

The United Nations special rapporteur on human rights in Myanmar, Yanghee Lee, said in a statement this week that Myanmar had come a long way since its transition began but significant challenges remained.

"I am concerned that journalists are still being interrogated and arrested, and that 10 journalists were imprisoned in 2014," she said. "This needs to stop if Myanmar wants to create a meaningful democratic space."