President Reynaldo Bignone tonight formally announced general elections will be held Oct. 30 and be followed by a transfer of power from the military to a civilian government in January. His television address is expected to launch a hectic race of reorganization and campaigning for Argentina's political parties.

Bignone, speaking after more than 10 days of formal meetings with political party leaders, said the new government would be inaugurated Jan. 30, 1984, almost eight years after the military took power. The transition date is two months earlier than the deadline for returning to constitutional rule fixed by the ruling military junta last June.

"The government is not contesting for power, it is giving it up," Bignone declared in his speech. He warned, however, of efforts to destabilize the process "that go from the rumor and the story to violence."

The announcement of election dates, long demanded by political parties but only reluctantly permitted by the military, has reassured many Argentine leaders who had feared the elections would ultimately be blocked by the armed forces. The military agreed to give up power a week after Argentina's defeat in the Falkland Islands conflict with Britain, but internal power struggles and hard-line opposition have threatened the plan ever since.

Political party leaders here said that a series of difficult issues remains to be resolved for a stable transition. Foremost among them are the military's future accountability for the failure of the Falkland Islands invasion and a campaign of internal repression during which an estimated 6,000 to 15,000 Argentines disappeared.

Bignone, who narrowly avoided a palace coup just two weeks ago, is also under severe pressure from military leaders who believe he has lost control of Argentina's political and economic leadership and allowed the armed forces to be "dishonored" by their opponents, according to sources close to the military.

Political leaders, who in recent weeks have conspicuously tried to bolster the position of the modest retired general, still fear Bignone may be ousted by tougher officers determined to restore the authority of the military before leaving office.

"The leadership has tried to give a little strengthening, a little oxygen to Bignone," said Luis Caeiro, a leader of the centrist Radical Party. "He really wants to end his government with a democracy, and if he is removed, no one knows what would come next."

The new political timetable emerged after a turbulent month of infighting among military leaders and confrontations between military and political leaders that led Bignone's government to the brink of collapse two weeks ago.

The armed forces, widely discredited politically by the Falklands conflict and severe economic problems, were shaken by strikes and major protests late last year and by increasingly sharp criticism by politicians seeking popular support. Under increasing pressure from angry commanders, the junta struck back earlier this month with a statement condemning a "campaign meant to dishonor the armed forces" and a series of actions to tighten its authority.

The junta, which holds ultimate power over Bignone and his government, threatened to put several leading politicians on trial for their attacks on the seven-year-old military rule, and imposed a set of conditions for Bignone to keep his position. Instead of negotiating the timetable for elections with the parties, as Bignone had planned, the junta dictated the dates and procedures in advance, according to political sources.

Party leaders defied the junta's threats of trials, but soon agreed to a series of high-profile meetings with Bignone at the presidential residence to discuss election plans. The meetings included leaders of Argentina's two most important parties, the Radicals and populist Peronists, who had earlier refused negotiations on the transition with the military.

Political sources said the meetings, which ended yesterday, were used by the parties and Bignone to strengthen his position among the myriad military factions.

"Nothing of significance was accomplished," one party organizer said. "But if we had not gone, the government would have been left too weak."

The election plan will leave only three months for the general campaign after completion of party reorganizations and internal elections in July. Political analysts believe as many as eight or nine parties could be certified.

The elections planned for October will choose a president, a bicameral Congress and provincial governors. The only parties now considered capable of winning the presidential elections are the Radical and Peronist groups, which have alternated with military leaders in power for more than half a century.

Both parties have been weakened and divided by the military rule and the death of strong leaders in the past decade. The Peronist movement, long the dominant force in Argentine politics and labor, has had particular difficulty reconciling factions ranging from the extreme right to the left since the death of leader Juan Peron.

Now divided between two main groups of leaders, allied with two confederations of labor unions, the Peronists must also resolve the role in the party of former president Isabel Peron, who will be allowed to return to Argentina in late March from exile in Spain.