Eight persons were arrested in the Washington area last night in what Montgomery County police called the breakup of a "major East Coast cocaine network."

A ninth suspect was arrested in Miami, Fla., and warrants for eight other persons were issued in connection with the case last night, according to Montgomery County police spokesman Phillip Caswell.

Caswell said the arrests follow a six-month investigation that began in Montgomery County. Officials could not estimate the value of the cocaine alleged to have been involved, he said, but described the operation as a "multipound cocaine distribution network."

The network allegedly received the cocaine in Dade County, Fla., and distributed it along the East Coast, Caswell said.

Caswell identified the "main target" of the inverstigation as Kerry L. Ricker, 30, of 5509 Devon Rd., Bethesda. Ricker, arrested last night, is employed as a real estate salesperson by Robert H. Kent Co. of Rockville. The Devon Road home is alleged to have been one of the main distribution points for the network, Caswell said.

Ricker's brother, Michael G. Bass, 28, an attorney, was the suspect arrested in Miami, Caswell said.

Police identified others arrested in the Washington area as Lionel Bailey, 38, of Forestville, a Bloomingdale's department store salesman at White Flint; Allen David Cohen, 38, of 2215 Kimble Pl. Silver Spring, owner of David's Beautiful People, a hair-styling shop in Rockville.

Also, David Clifford Hegeman, 32, of Lanham, a hairstylist employed at David's; Deborah Stocks 25, of 2770 Hyson La., Fairfax, a copywriter for Needham Harper Steers Advertising in Falls Church; Peter Balancho Jr., 36, of 301 N. Beauregard St., Alexandria, a self-employed salesman; Harriet Brill, 30, of 3701 Massachusetts Ave. NW, a language instructor at International Language Institute of Washington, and Dean Gust Trakas, 28, of 3911 Abington St., Arlington a food and beverage manager for St. Tropez Lounge in the District.

All were charged with conspiracy to distribute a controlled dangerous substance. Ricker was charged with four counts of distribution of cocaine and conspiracy to distribute cocaine. Bailey was charged with possession with intent to distribute cocaine and conspiracy to distribute hashish.

All were released on bond.