Nathanson Quits Coastal Panel : Appointees: Brown says he received resignation letter from the indicted commissioner two weeks ago. Beverly Hills real estate agent Diana Doo will fill the vacancy.

Faced with an eight-count criminal indictment for abuse of public office, California Coastal Commissioner Mark L. Nathanson has resigned from his appointive post, Assembly Speaker Willie Brown (D-San Francisco) disclosed Monday.

Brown, who named Republican Nathanson to the coastal panel in 1986, said he received an undated resignation letter from his appointee almost two weeks ago. The Speaker did not explain why he delayed announcing the departure of Nathanson until this week, four days after the indictment.

To fill the vacancy created by the resignation, Brown named Nathanson’s alternate on the commission, Beverly Hills real estate agent Diana Doo. Nathanson named her as his alternate on the commission in December, 1990.

A federal grand jury last Thursday accused Nathanson of using his office to extort payments from those seeking permits from the commission, beginning in March, 1986--just months after Brown named him to the post.

The indictment charges Nathanson with extortion, racketeering, obstruction of justice and tax evasion. The grand jury alleged that he attempted to extort payments from some of the most powerful figures in Hollywood--including “Rocky” star Sylvester Stallone, who turned down a demand for $25,000, and “Rocky” producer Irwin Winkler, who paid $50,000. Both had appliedto the commission for permits to make improvements on their Malibu homes.

Brown, who had been under pressure for months to remove Nathanson from office after reports of a federal investigation, said that he did not request the resignation.

“Everybody I appoint to anything knows when they should quit, if it’s a necessity for them to quit,” Brown said. “He’s no different.”

Brown added: “I had no discussion with him, he mailed it in. . . . It just says ‘I resign.’ There’s no confession in it.”

Last week, immediately after the grand jury action, Brown’s office said he would have no comment on the plight of his appointee.

On Monday, Brown spoke lightly about holding the letter for some time before releasing it.

“I’m keeping it a secret,” he said with a laugh. “I want you guys to make fools of yourselves”--a reference to reporters and editorial writers who have been asking when Brown would act to remove the indicted coastal commissioner from office.

When asked whether the resignation letter was on file with the Coastal Commission, Brown made it clear that the post was his, and his alone, to dispose of.

“I’m the appointing authority, not the commission,” Brown said. “He doesn’t resign from the commission, he resigns from me.”

As Speaker, Brown names four of the 12 members to the panel, which regulates development and beach access along California’s 1,100-mile coastline. Like the eight other members--four named by the governor, four by the Senate Rules Committee--the Speaker’s appointees can be removed at any time and for any reason.

In announcing the charges filed against Nathanson, U.S. Atty. George L. O’Connell said there was no evidence that Brown “had anything to do with the charges that are alleged in this indictment.”

Through his attorneys, Nathanson has asserted that he has done nothing wrong and expects to be vindicated on all charges.

He plans to plead not guilty when he is arraigned May 27, said his attorney, Stephen L. Braga.

Braga said Nathanson was advised that if he was indicted “it would require a substantial amount of his time to help lawyers prepare a defense to the charges and that might be a consideration for him to take into account in deciding whether to stay on the commission.”

The undated resignation letter, postmarked in Los Angeles on April 22, only states Nathanson’s intention to leave his public position without referring to the dramatic circumstances surrounding his departure.

“Dear Mr. Speaker,” Nathanson wrote, “I hereby resign as your appointee to the state Coastal Commission. Thank you for allowing me the opportunity to serve. Sincerely, Mark Nathanson.”

Nathanson, 52, is a Beverly Hills real estate broker. He has made his money in commercial real estate and by buying, remodeling and selling homes in high-priced areas. Serving on the commission is a part-time job--the panel meets monthly, usually for a four-day session. Commissioners are paid $100 a day for meetings, plus expenses.

Brown’s press secretary, Jim Lewis, said the Speaker “normally accepts the resignation of any appointee who wishes to resign. That is his practice.”

Critics of Nathanson--including Assemblyman Tom Hayden (D-Santa Monica) and a number of environmental groups--have complained about the commissioner’s generally pro-development votes and have been calling for his removal from office for years. Hayden first asked Brown to replace Nathanson in 1987.

Madelyn Glickfeld, a Senate appointee to the commission who has often clashed with Nathanson, expressed relief that he had stepped down, saying his presence “had cast a pall over the commission.”

“It’s a chance for the commission to start over again,” Glickfeld said. “It’s been a very long six years.”

Times staff writer Mark Gladstone contributed to this report.