President Julio Cesar Turbay Ayala today appointed a commission of nine lawyers charged with finding a way to speed up the trials of more than 200 persons accused of leftist political activities. This was the first concession the government has made to the M-19 guerrillas who seized the Dominican Republican Embassy here two weeks ago.

The guerrillas' principal demand to ensure the safe release of an estimated 32 hostages, including 12 ambassadors, held in the embassy had been the release of 311 "political prisoners" accused or convicted of subversive acts. Those among the 311 who are still alive are believed to be on trial now before military courts or serving sentences in Columbian jails.

It is known, however, that the guerrillas have reduced their demands to the release of 70 political prisoners and a $10 million ransom.

Until now, the Turbay government has taken an uncompromising position toward the M-19 demands, refusing to consider the release of prisoners or pay any part of a $50 million ransom the guerrillas initally demanded.

Today's decision to appoint the commission was interpreted by informed sources as the first break in the stalemated situation since it began Feb. 27.

The creation of the commission came after a meeting yesterday between Colombian Foreign Minister Diego Uribe Vargas and diplomats representing the 12 countries whose ambassadors are being held hostage. Among the ambassadors in Diego C. Asencio of the United States. h

Informed sources said the diplomats told Uribe that they felt the government's previous position -- that Colombia's laws and constitution prohibited the release of any prisoners before their trials were completed or their sentences served -- was overly legalistic. The diplomats reportedly told Uribe that there were legal loopholes if the government wished to find them.

An official communique issued tonight said that the commission's only role was to find a way to speed up mass trials for more than 200 leftists now underway in Bogota, Barranquilla and Cali. But Alfredo Vasquez Carrizosa, a former Colombian foreign minister who met with the guerrillas on the first night after the embassy seizure said that the lawyers may search for ways to break the impasse beyond simply speeding up the trials.

One informed source said that he expected the commission to take 10 to 15 days to make its recommendation. This was enough time, the source said, "to convince the military and public opinion" here that the release of some prisoners was a necessary concession to avoid a possible bloodbath at the embassy.