A $5,000 reward is being offered by Time-Life Books Inc. for information leading to the arrest and conviction of the person or persons responsible for the death of Constance C. Mellon, Alexandria police said yesterday.

Mellon, a 36-year-old employe of Time-Life, was found bound and shot to death in her rented, two-story town house at 406 S. Royal St. last Tuesday. dShe had moved into the house Oct. 3, and was last seen alive that day, police said.

So far, they have no motive for the killing and no suspects, police said yesterday.

Mellon, who had worked in the production department of Random House Books in New York for the last 10 years, moved to Alexandria Sept. 14 for a position with Time-Life. She had been living in the Old Town Holiday Inn at 480 King St. before moving to the small town house.

One neighbor said she heard loud music coming from a radio in Mellon's town house Saturday evening. A family member said Mellon had planned to meet her sister in New York Saturday morning, but never arrived. So far, police have been unable to determine the time of death.

Mellon was found by Time-Life co-workers Tuesday, lying on her bed under a blanket. She had been shot once in the head with a small caliber pistol. Her hands were tied behind her.

Anyone with information is asked to call the criminal investigation division of the Alexandria police at 750-6470 or 750-6417.