SAO TOME, Sao Tome e Principe (AP) _ On this tiny equatorial island used as a way station for the slave trade, Pope John Paul II on Saturday deplored the Roman Catholic Church's condoning of that ''sad offense'' to human dignity.

The pope celebrated an open-air Mass for nearly 40,000 people, about one- third of the predominantly Catholic country's population.

Sao Tome e Principe consists of two islands about 200 miles west of Gabon. It initially was settled by Jewish children deported from Portugal during the Inquisition. It then became a transit point for the slave trade, and other slaves were brought in to work on the islands' plantations.

During his nine visits to Africa, John Paul has consistently apologized for the church's role in the slave trade.

''I cannot but deplore this cruel and sad offense to the dignity of the African man,'' the pope said Saturday.

Sao Tome e Principe established a Marxist government after gaining independence from Portugal in 1975, but since 1991 it has been moving toward market-oriented democracy. The impoverished country's economy is based entirely on agricultural exports.

President Miguel Trovoada told John Paul that the precarious state of the economy ''threatens democracy itself and creates an extremely serious situation.''

The government removed milk and oil price supports two months ago as demanded by Sao Tome's international creditors, and the public responded with two days of demonstrations. Trovoada was forced to replace the prime minister, Daniel Daio.

''The exaggerated selfishness of some countries causes the degrading misery of others,'' Trovoada told the pope, referring to World Bank demands that the country keep to its schedule for repaying its $250 million foreign debt.

In a gesture to salute the pope's arrival, Trovoada proclaimed a pardon for minor crimes and appointed the first chief justice of Sao Tome's first Supreme Court.

But he also raised gasoline prices nearly 25 percent, to about $1 per liter, or $4 a gallon.