The U.S. rate of attempted rapes of girls and women decreased 46 percent from 1973 to 1987, although the rate of completed rapes stayed the same, according to a study released yesterday by the Justice Department.

Author Caroline Wolf Harlow said the rate of attempted rapes declined from 1.3 per 1,000 girls and women in 1973 to 0.7 per 1,000 in 1987. The rate of completed rapes was unchanged at 0.6 per 1,000, Harlow said.

Criminologist Alfred Blumstein theorized that the decline could be attributable to heightened male sensitivity to concerns raised by women. But he noted that many women are still reluctant to report the crime, making statistics unreliable.

Rape accounted for 3 percent of all violent crimes measured by the survey, according to the report, "Female Victims of Violent Crime."

Only 53 percent of rapes or attempted rapes are reported to police, the study said. But the survey estimated there were 137,509 rapes and attempted rapes in 1987, down 14 percent from 159,890 in 1973.

Women were more likely to call police if raped by a stranger than by someone they knew. Among women who were raped in or near their homes, 48 percent said the attacker was someone they knew, the study found.

The survey found that women were six times as likely as men to be victims of violent crime by a current or former spouse or companion.