FBI agents yesterday arrested six persons on racketeering charges in connection with what authorities described as the Washington area's largest commercial prostitution ring, allegedly operated out of seven massage parlors in the District of Columbia and suburban Maryland.

The arrests followed a 57-count federal grand jury indictment returned Wednesday and naming nine codefendants in an alleged ring that had profits of about $80,000 a month and involved 75 prostitutes.

William M. Hohman of 1738 Lanier Pl. NW was also indicted in D.C. Superior Court on a separate charge of being an accessory after the fact to the slaying of another alleged participant in the operation two years ago.

Arrested yesterday were Hohman, 46, who described himself in a U.S. District Court hearing as the manager of the Spectrum Restaurant at 919 11th St. NW; Ira Louis Mayerson, 49, of 15201 Middlegate Road, Silver Spring; his wife, Harriet Ruth Mayerson, 45, who allegedly acted as the operation's bookkeeper; Lonnie Walter Johnson, 30, of 1436 W St. NW, an alleged courier for the group, and alleged massage parlor managers Gerald Whitaker, 40, of 9737 Mount Pisgah Rd. in Silver Spring and John Arthur Collet, 34, of 2230 Kingslanding Rd., Huntingtown, in Calvert County.

Hohman and Ira Mayerson were alleged in the indictment to be the leaders of the operation.

Bench warrants were issued yesterday for the arrests of Raymond Robert Hager, 29, another alleged massage parlor manager; and Tina Louise Kempa, 23, charged with interstate transportation in aid of racketeering.

The ninth person named in the indictment was Arthur Chester Morgan, 31, alleged to be a former massage parlor manager. Morgan is currently serving a 30-year sentence in the Maryland State Penitentiary in Baltimore after his conviction last year on a charge of second-degree manslaughter in the shooting death of George Robert Alston, 44, of Oxon Hill in October 1981.

Hohman, the two Mayersons, Whitaker and Collet pleaded not guilty to all charges in hearings before a federal magistrate yesterday. Hohman was ordered held on $25,000 bond, and the others were released on bonds ranging from $10,000 to $25,000.

A D.C. Superior Court judge later placed an additional $15,000 bond on Hohman for the accessory to murder charge.

Johnson, Hager, Kempa and Morgan could not be reached for comment yesterday.

The separate indictment against Hohman charged him with helping to hide Morgan in some of the massage parlors after the slaying.

According to the racketeering indictment, Morgan managed the Oriental Bath and Health Spa in Camp Springs and was employed by Hohman to act as an "enforcer" to "use or threaten to use violence in conducting the affairs of the enterprise."

On Wednesday, federal officials obtained court orders freezing assets totaling $1.6 million dollars in 17 bank accounts the FBI said contained profits from alleged prostitution activities.

According to the indictment, Hohman and the Mayersons directed a sophisticated network of interlocking companies out of District and suburban offices that received receipts from the massage parlors and laundered the profits.

The massage parlors were operated on a strictly business basis, including billing customers on credit cards and teaching prostitutes, called "hostesses," how to solicit tips from customers and keep itemized records, according to the indictment.

At the massage parlors, FBI officials alleged, a customer usually was given his choice of a hostess, who led him to a private room, showed him erotic movies and negotiated payment for sexual favors.

Customers paid in advance, either with cash or credit cards. A percentage of the receipts was returned to the women as salary, the FBI said.

According to the indictment, the massage parlors involved in the ring were the Adam and Eve Model Studio, 804 14th St. NW; the Paradise Escort and Model Service, 810 14th St. NW; the Geisha House, 2009 K St. NW; the Bath House, 7616 Georgia Ave. NW; the Eden, 921 11th St. NW; the Oriental Bath and Health Spa, 5920 Allentown Way, Camp Springs, and the Sun Spa, 1819B M St. NW.

Early last year, agents from the FBI and the Internal Revenue Service executed a series of search warrants on the massage parlors as well as the defendants' residences and offices. Since then, all of the massage parlors except the Adam and Eve and the Paradise have closed or been sold, FBI officials said.