Americans reported 1 percent more crime in the first half of this year to law enforcement agencies than in the first half of 1986. It was the lowest increase in three years, the FBI reported yesterday.

By comparison, reports of crime rose 8 percent in 1986 from the same period in 1985 and had risen 3 percent in 1985 from 1984.

But the three years show a rise in the crime rate over the years 1984-1983, when the Federal Bureau of Investigation reported a 5 percent drop in crime nationwide.

While property crime rose 2 percent, violent crime dropped one percent during the comparable 1987 and 1986 periods, according to data provided to the bureau's Uniform Crime Reporting Program by law enforcement agencies nationwide.

The South reported the greatest crime rise -- 3 percent in the first half of 1987 compared with the first half of 1986, followed by the northeastern states, with a 2 percent rise in crime reported for the same months.

Western and midwestern states reported less crime than the rest of the country, the bureau said, and crime totals there remained unchanged this year over last.

The nation's rural areas and cities with populations under 10,000 also reported no change in crime for the comparable time periods of this year and last.

But the picture changed for cities of larger populations and their suburbs, the FBI index shows, with these cities reporting crime rises ranging from one percent to 3 percent, and their suburbs showing a one percent climb in crime.

Of the violent crime reported, the only increase was in aggravated assault, up 2 percent. Murder declined by 2 percent, while robbery dropped 5 percent. Forcible rape showed no change.