Angola has closed down the Roman Catholic radio station in the southern African nation and the government newspaper has attacked the Catholic bishops for drawing up a "provocative, insulting, slandering and reactionary document" attacking the country's Marxist rule.

In a dispatch from Luanda, Agence France-Presse reported that a decree of President Agostinho Neto on Wednesday shut Radio Ecclesia and nationalized all of its assets.

It appeared to be the sharpest church-state conflict since the Movement for the Popular Liberation of Angola consolidated power in 1976 after Portugal pulled out of its former colony.

An estimated 40 per cent of Angola's 6 million people are Catholic, which was the state religion under the Portuguese. Another 15 per cent are Protestant and 45 per cent practice African religions.

The decree seizing the radio station said Angola is now constitutionally a secular state and that all news outlets must be under government control.

At a recent meeting, the bishops produced a letter criticizing the alleged failure of Neto's government to assure the constitution's guarantee of freedom of religion.

The bishops also attacked the newly formed MPLA Labor Party - structured closer to traditional Marxist-Leninist lines than the ruling Popular Movement itself - as "atheistic."

Church officials in the United States were at a loss to explain precisely what provoked the bishops. According to the version in the official Jornal de Angola, they accused the state of "sacrilegious profanation" of churches.

Isaac Bevins of the United Methodist Church mission office in New York described his church's affiliates in Angola as having "a very open relationship with the government. The church has been permitted to carry on its work" although he said it earlier efforts in basic education have been taken over by the government.

Several religious visitors since 1976 have affirmed positive relations there. A task force of 35 Methodists leaving for Africa next month to evaluate programs plans to visit Angola.

Jornal de Angola, in its editorial titled "Bishops and Conspiracy, " said that the Catholic hierarchy had distributed its letter to congregations and released it abroad without presenting a single copy to the state.

Neto in the past has promised that churches would be allowed full freedoms. His own background is Protestant.