* Rank-and-file officers demand higher wages
* Argentine inflation clocked at over 20 percent per year
* Massive protests against gov't economic policy last month
By Hugh Bronstein and Guido Nejamkis
BUENOS AIRES, Oct 3 (Reuters) - Argentina's coast guard and military police held unprecedented wage protests on Wednesday, prompting the government to fire the heads of both services while Congress called for an orderly resolution of the dispute.
Strikes over wages are common in Argentina, where inflation is running at more than 20 percent annually, according to private economists.
But this was the first time in memory that uniformed Argentine military forces have taken to the streets over wages. Talks aimed at ending the dispute reached late into the night.
"We support democracy. This is not a political uprising. It's nothing strange," military police officer Fernando Parodi shouted into a bullhorn at a rally in front of military police headquarters in Buenos Aires, where hundreds of olive green-clad officers chanted slogans in solidarity.
"We are workers, like any others, who need to support our families," Parodi said.
The top leaders of Argentina's military police and coast guard were replaced by the government earlier in the day.
The protests started on Tuesday when officers demonstrated against an administrative measure that cut some of their pay checks by up to 70 percent. The strike soon morphed into a demand for higher wages generally.
The government promised to revise the measure that sparked the protest. Cabinet Chief Juan Manuel Abal Medina said violence would not be tolerated and Congress issued a statement calling on the striking officers to conduct the protests "within the confines of democracy."
The officers assured the country that basic coast guard and military police duties, particularly at border crossings, continued to be carried out despite the protests.
Buenos Aires provincial Governor Daniel Scioli issued a statement calling for calm. "It's time to reflect, go back to work and to the sensitive responsibilities that have been entrusted to you as members of our security forces," it said.
President Christina Fernandez's popularity sank to 24.3 percent in September from 30 percent in August.
A year ago, just before winning her second term, she had 64.1 percent popularity while campaigning on a promise to expand on the policy model of her late husband and predecessor, Nestor Kirchner, who increased the government's role in the economy.
After winning re-election in October, Fernandez imposed new currency controls to stem capital flight and the investment climate also took a hit when her government seized a majority stake in the country's No. 1 energy company YPF.
With the economy of the grains-exporting country hampered by fallout from Europe's debt crisis, slow demand from key trade partner Brazil and low soy output caused by a December-January drought, Argentines are increasingly worried about inflation. So disputes over wages are likely to continue.
Tens of thousands from all walks of life rallied in major cities last month to protest policies such as the de facto ban on buying foreign currency and a possible bid to overhaul the constitution so Fernandez can run for a third term.