The M19 guerrilla movement always has had a knack for attracting attention.

Although much smaller than the pro-Moscow Colombian Revolutionary Armed Forces, the M19 already was renowned for spectacular actions before its bloody attack last Wednesday on the Palace of Justice here.

The group took its name from April 19, 1970, the date when populist ex-president Gustavo Rojas Pinilla lost what M19 supporters charge was a rigged election. In subsequent years, many young people from his party went underground, and M19 is generally said to have formed in 1973 or early 1974.

In April of that year, members of M19 stole the sword of Simon Bolivar, the 19th-century South American liberator. In 1979, they made off with 5,000 weapons in a raid on a major military arsenal. The guerrillas caught world attention in February 1980 by seizing 52 hostages, including the U.S. ambassador and a dozen others, at a reception in the Dominican Republic's embassy here in February 1980. The hostages were freed 61 days later, and the guerrillas flew off to Cuba.

M19 has sought to portray itself as reformist, forced to take up arms by what it calls official intransigence. Spokesmen say they are more influenced by Colombian novelist Gabriel Garcia Marquez's vision of the nation than by Karl Marx. Garcia Marquez has characterized himself as Marxist.

Founder Jaime Bateman Cayon died in an air crash in April 1983, and Carlos Toledo Plata, who had accepted a government amnesty and was working as a government-employed physician, was assassinated in August 1984 outside his home.

That same month, M19 leaders provisionally accepted a government-proposed cease-fire, but in June this year formally broke off official talks and returned to the underground, accusing the government of failing to implement promised reforms. In recent months, the movement has launched attacks in southwestern Colombia, provoking Army counterattacks.