France announced today that it is sending another 1,000 troops to its troubled Pacific territory of New Caledonia to reinforce law and order following the declaration of a state of emergency on the island.

The decision to send the mixed contingent of gendarmes and paramilitary police to the island was made at an emergency meeting of senior ministers chaired by Prime Minister Laurent Fabius in Paris. The reinforcements will bring the size of the island's internal security force to 3,280 men, in addition to 3,000 French soldiers and 300 local gendarmes who can also be called up if necessary.

Today's declaration of a state of emergency followed the shooting by police of two leading Kanak separatists and riots in the capital, Noumea, by largely white demonstrators incensed at the murder of a European farmer yesterday at Thio. It was the first time such measures have been taken in a French-ruled territory since 1961, when Charles de Gaulle assumed full powers to deal with a settler insurrection in Algeria.

In a statement, Fabius pleaded with New Caledonia's population of 145,000 indigenous Kanaks, European settlers and largely Asian immigrants not to allow themselves to be drawn into "an infernal cycle of violence."

Reports from Noumea this evening said that the streets of the town were deserted following the imposition of a nighttime curfew. Troops were guarding the residence of the government delegate, Edgard Pisani, who devised a plan designed to lead to independence for the island "in association with France" from the beginning of 1986 following a referendum in July.

The dramatic increase in tension in New Caledonia over the last two days has undermined hopes of the Socialist government in Paris for a peaceful transition to independence for the territory, which has been ruled by France since 1853. It has also stirred unpleasant memories here of the civil war in Algeria in the late 1950s and early 1960s and the mass exodus of that country's white settler population following the granting of independence.

While the scale of the two episodes in France's colonial history is clearly different, with most French people considering New Caledonia a faraway speck in the Pacific Ocean, the process of political polarization has been somewhat similar. The government here has come under attack from the right-wing opposition for its alleged lack of firmness in suppressing the separatist movement.

In his statement, Prime Minister Fabius endorsed Pisani's proposals as "in the interests of all the communities on New Caledonia." However, support for the plan appeared to be dwindling in New Caledonia following the sudden upsurge of violence and the hardening of attitudes on both sides.

Jean-Marie Tjibaou, president of the self-proclaimed "provisional Kanak government," said that the killing of the two separatists was a "barbarous act" that "created a new situation in the struggle of the Kanak people for its independence." He made clear that he was withdrawing his party's earlier partial endorsement of the Pisani plan.

The most prominent of the two separatists killed in the shootout with police was the leader of a hard-line Kanak seperatist group, Eloi Machoro, 38, who had been named "security minister" in the "provisional government." Police said the two had refused to surrender during a riot in the west of the island. Machoro had made two trips to Libya during the past two years to seek support for the independence movement.

French officials said that 19 persons have died in New Caledonia as a result of the political upheavals that followed the election of an island assembly last November. The elections, which were boycotted by the separatists, were won by a right-wing Gaullist party which favors continued union with France.

The mounting opposition to Pisani's attempts to bring about a compromise between the rival communities jeopardizes the Socialists' hopes of getting the New Caledonia crisis out of the way before the holding of legislative elections in France in early 1986. If, as at present seems likely, those elections are won by the right, the entire independence process could be blocked.

Pisani's proposals envisage France giving up sovereignty over the island but retaining responsibility for internal and external security. The secretary general of the neo-Gaullist party, Jacques Toubon, said today in Paris that his party would soon put forward its own proposals for dealing with the crisis.