Sen. Herman E. Talmadge (D-Ga.) said yesterday that he would comply with a request from the Senate Select Committee on Ethics and appear under oath before the panel to answer allegations of financial misconduct that have been raised against him.

Talmadge's unexpected decision reversed an earlier stand taken by his attorneys last week after the committee called for his appearance under oath. At that time, Talmadge's attorneys said that during six weeks of hearings the ethics committee had failed to establish enought of a case to warrant an appearance by the senator.

After meeting in closed session for two hours yesterday, the committee repeated its request. The panel deliberately sidestepped the touchy issue of whether to issue a subpoena to force Talmadge, a 23-year Senate veteran, to appear. But it left open additional moves if Talmadge declined to come forward voluntarily.

In a two-page reply issued late yesterday Talmadge said he would appear and would present additional evidence including a lengthy list of witnesses. He said his earlier decision not to come before the committee was based on his efforts to avoid "painful, private matters relating to my personal and family life."

"The committee has made it impossible to do this," Talmadge said.

A committee spokeswoman said Talmadge's late decision would require the panel to postpone resumption of the hearings until July 9.

She said Talmadge would be questioned by committee special counsel Carl Eardley when he appears. Before the hearings began, Talmadge issued a statement calling for direct questioning by committee members rather than by Eardley if he elected to appear under oath.

Talmadge's decision will focus attention on at least two major unresolved items that have come up during the long-running hearings.

The committee is likely to question Talmadge about the mysterious cache of $100 bills that his former wife Betty said he kept in his residences since the 1940s when he was governor of Georgia. During her appearance before the committee, Betty Talmadge said the amount of money in the secret cache sometimes rose to $45,000 or more.

Last fall, when he appeared under oath during a closed committee session, Talmadge told the ethics panel he lived off small cash gifts of $5 and $10 given to him by supporters in Georgia. At the time he did not memtion anything about the secret cash hoard.

The committee is also likely to pursue the question of the authenticity of two memoranda turned over to it by former Talmadge aide Daniel Minchew. The memos link the senator to knowledge of a secret bank account that Minchew said was used to funnel inflated Senate expense payments and unreported campaign contributions to Talmadge.

Allyne Tisdale, Talmadge's current financial secretary and the purported author of the memos, denied under oath to the committee that she prepared them. Talmadge has labeled Minchew an embezzler and has denied any knowledge of the secret bank account.