A Frederick, Md., man whom police say headed a prostitution ring that catered to "hundreds" of men in the Washington area pleaded guilty yesterday in Montgomery County Circuit Court to a charge of conspiracy to violate pandering laws and was fined $1,000 by Judge John J. Mitchell.

Three other pandering charges against Frederick Phillip Class, 41, were dropped yesterday. Pandering is defined as accepting money derived from prostitution, according to law sources.

"I'll try to give you a deterrent from getting involved in this kind of thing again," Judge Mitchell told Class, who had run a telephone referral service known as "Sherrie's Enterprises" at the time of his arrest last Sept. 14.

Class could have received 10 years in prison and a $5,000 fine, according to deputy Montgomery County States Attorney Timothy E. Clarke, who prosecuted him.

According to police the payment of a $45 fee to Sherrie's Enterprises enable a male customer to go to a woman's home of office for what was billed as a "Massage" but was in fact an act of prostitution.

The names of dozens of men, believed to have been customers of the operation, and the names of dozens of women, believed to have been prostitutes, were reportedly seized by county vice officers when they raided Sherrie's Enterprises, located at 15976 Shady Grove Rd., last fall, police said at the time.

Coded record of the clients' sexual preferences also reportedly were taken from the red-carpeted offices. The lists of names has never been released by police.