SAN FRANCISCO (AP) _ Hundreds of thousands of doses of LSD - nearly one-fifth of the nation's supply of the hallucinogenic drug - were produced each year since the 1960s by a ring led by four people who have been arrested, federal officials said.

The raid Friday by the Drug Enforcement Agency coincided with an unrelated raid by the state attorney general's office that found 41,400 doses of LSD, and gave further support to claims by officials that the San Francisco Bay area is the primary source for the drug in the nation.

DEA agents on Thursday confiscated 1.6 million dosage units of LSD, 8.8 pounds of high-grade marijuana, 1.5 pounds of cocaine and $50,000 in U.S. and foreign currency in Sausalito, Sebastopol and San Francisco. The street value of the drugs was estimated at $5 million.

''This is one of the largest cases in the country,'' Dick Mangan of the DEA said Friday.

The DEA identified those arrested as Diane Stepak, 49, of San Francisco; Bernard Hassall, 43, of Sebastopol, and Glen McKay, 49, of Sausalito. Mrs. Stepak's husband, Paul, a physician, was arrested when he turned himself in on Friday. Agents said more arrests are expected.

Agents also found ''extremely sophisticated processing equipment'' while raiding Hassall's homes, Mangan said.

The processing plant included computers and custom-made equipment, Mangan said, adding that the machines could even stamp each pill with a ''YES'' or ''LSD-100'' logo.

LSD stamped with the ring's logo has been found from Hawaii to New England, said DEA spokesman Dennis Petrotta. The agency said it believes the breakup of the ring ''will have a significant impact on the availability of LSD,'' which agents said is becoming more popular.

''The LSD field is making a comeback,'' said DEA special agent Joseph Kruger. ''Eleven to 12 million dosage units are taken annually in the country by about a million users.''

U.S. Magistrate Wayne Brazil ordered the four held until Wednesday, when he will rule on a government request to continue holding them without bail.

A conspiracy charge was filed only against McKay, related to an alleged agreement with Hassall to sell a small amount of LSD, according to a sworn statement by DEA Agent Thomas Ma.

All four were charged with possession of narcotics with intent to distribute. Conviction carries a maximum penalty of 15 years in prison and a $250,000 fine.

The state attorney general's office Friday confiscated 41,400 doses of LSD in one raid and an ''undisclosed amount'' in another, said spokeswoman Kati Corsaut.

Agents arrested Lon Kent Davis, 35, at the Berkeley Marina for allegedly selling $100,000 worth of the drug to undercover agents. Davis is being charged with six counts of the sale of LSD, Corsaut said.

Seven other people were arrested in connection with processing the drug, she said.