Spain's sprawling and depressed southern region of Andalusia yesterday narrowly failed to approve home rule despite a substantial majority vote in favor on the issue.

The home rule referendum was blocked in two provinces, where the vote in favor fell below the 50 percent required in all provinces for talks on self-government to be initiated with the Madrid government.

The overwhelming overall majority vote of approvl for home rule, however, was a moral victory for the Socialists and Communists who had campaigned for passage.At the same time, the narrow margin of defeat was a blow to the prestige of the government which had urged voters to abstain.

The consequences for the government were particularly serious in the context of elections to regional parliments in the Basque country and in Catalonia within the next two weeks.

Yesterday's referendum also undermined the heightened political and social tensions in what is Spain's poorest region.

The "yes" vote fell short in the provinces of Almeria, the most sparsely populated in the region, and of Jaen, the poorest province in the whole of Spain, where the vote endorsing self-government fell below 50 percent of the total census. The constitutiton provides that an absolute majority is required in every province for home rule negotiations to be initiated between the region and the congress.

In the remaining six provinces of Andalusia, the home rule campaigners carried the day with a high turnout in the densely populated province of Seville, where 65 percent of the provincial census voted in favor of regional autonomy. Taken as a whole, 55.4 percent of the region's 4.4 million registered voters endorsed home rule, leaving no doubt as to the strong feelings in favor of autonomy in the area.

The Union of the Democratic Center government, headed by Prime Minister Adolfo Suasraz, had urged an abstention in Andalusia after a controversial policy document last month by the party's executive recommended that the decentralization process, upon which Spain embarked after the death of dictator Francisco Franco and the restoration of democracy, ought to be slowed down and more carefully thought out. The policy decision caused the resignation from the party of an Andalusian Cabinet minister and a deep split among party members in the south.

Although the Socialist and Communist opposition has publicly recognized the need for a rational approach to decentralization -- in itself the single most ambitious and delicate aspect of Spain's transition to full democracy -- both parties seized on the Andalusia referendum as a test of the government's credibility and whipped up popular feelings in the region by arguing that the south was the victim of discrimination.

The result was what centrist politicians claimed to be a demagogic campaign by the leftists which saw home rule extoled as a panacea for Andalusia's cronic underdevelopment.

The concern in Madrid over the referendum outcome is all the greater because of the Basque and Catalan regional elections due March 9 and March 20. Opinion polls there already show Center Party candidates trailing behind nationalists and the left. At issues, particularly in the Basque country, is the pace and extent of decentralization and the dismemberment of the tight uniform control from Madrid imposed under Franco.

In the Basque country, a nationalist majority could be elected to the regional parliament and raise the question of separatism by making unacceptable demands for local control. In Catalonia, a socialist regional government with Communist backing would inevitably mean the effective loss by Madrid centrist administration of political control over Spain's richest and most developed area.

Had an absolute majority been gained in every one of Andalusia's eight provinces, the region would have gained the right to negotiate a statute of autonomy, complete with a regional parliment and government, similar to that currently in force in the Basque country and in Catonia. Since that mandate was not achieved, Andalusia can nevertheless negotiate a less ambitious self-government bill which in time will be extended to include a regional assembly.