Behind a facade of calm, residents of this West African capital express anger at static wages and spiraling prices just after two-thirds of the nation's annual budget was spent to host the annual Organization of African Unity summit this month.

The circumstances in Sierra Leone parallel, in part, those that led to the April overthrow and assassination of William Tolbert, the president of neighboring Liberia. A year ago, Tolbert spent half his nation's budget to host the 1979 OAU summit shortly after riots broke out over government proposals to increase the price of rice, a staple for both Liberians and Sierra Leoneans.

The tensions in Sierra Leone erupted into four days of rioting last March and spread to the northern interior city of Makeni after the government raised the price of gasoline 33 percent, from $2.25 a gallon to $3. At least two persons were killed by police.

Sierra Leonean President Siaka Stevens said he expects "more trouble" if he makes the hard, yet unavoidable decision to raise gasoline prices again.

"We will be considering another" gasoline price increase this week, said Stevens, who is also this year's OAU chairman. "We don't know what is going to happen."

A poor tropical country of 3 million people, Sierra Leone, like many other West African countries, has been severly hurt by rising oil prices and declining domestic agricultural production.

As in Liberia, Sierra Leone's economic unrest and poverty may be aggravated by its expensive stint in the limelight as host of the OAU summit, which cost this country $200 million to organize and stage.

The Liberian military coup was complicated by the political and economic dominance of the ruling minority caste of settler Americo-Liberians, descendants of freed slaves from America who settled the country in the 19th century and ruled the majority of indigenous Africans.

Like Liberia, Sierra Leone has its own minority of "settlers," called Creoles, made up of 60,000 descendants of Africans freed from slave ships by the British Navy in the 19th century. Unlike in Liberia, however, the Creoles have been politically insignificant since Sierra Leone's independence in 1961.

Stevens agreed that there were economic similarities between the two countries -- "We are politically independent but economically weak," he said -- but rejected any political comparisons.

Stevens, a descendant of the Limba and Temne people -- two of sierra Leone's 18 tribes -- said he frequently warned Tolbert, a third-generation American-Liberian, to open up Liberia's political system to indigenous Africans. Tolbert was trying to respond to the demands of the indigenous people, Stevens added, but the changes came too late.

On the cost of the OAU summit to Sierra Leone, at a time when the country is expected to have more than $100 million deficit this year, Stevens argues that it was a popular decision.

"This OAU business was passed by parliment," said Stevens, who head the only legal party in Sierra Leone, the All People's Congress. "Everyone was happy," he said, "I put them on the map."

The country momentarily broke into the headlines earlier this year when it was revealed that Stevens was negotiating with an American company, Nedlog Technology Group Inc. of Arvada, Colo., to accept the dumping of millions of tons of hazardous chemical waste in Sierra Leone for a reported $25 million a year. The news reports of the dumping proposal raised a storm of protest in West Africa, and Stevens hastily dropped it.

Once a leading West African education center, Sierra Leone's capital, Freetown, has languished in 19 years of postindependence obscurity. The city's distinct Victorian cottages, narrow horse-and-buggy streets and the mountaintop vista of Fourah Bay College evoke faded glory: it was called the "Athens of West Africa" at the turn of the century.

The weathered red-brick, white-trimmed houses of the Creoles are now interspersed with the shanty metal-walled slums of the 20th century cursh of peasant migrants. The cramped streets are perpetually clogged with traffic jams. Fourah Bay College, founded in 1827, has fallen from its former prominence.

Since winning election as an opposition leader in 1967, Stevens continually has had to suppress cycles of domestic turmoil focused on Freetown. He had to flee the country to neighboring Guinea shortly after his election following an anti-Stevens Army coup. A noncommissioned officers' mutiny returned him to power a year later.

Starting in 1968, there have been four states of emergency, two more coup attempts and two assassination attempts as Stevens tightened his strongman rule. In 1975 eight men were executed following conviction of involvement in an assassination attempt, and in 1977 antigovernment sutdent protests rocked the government.

A great deal of the unrest in Sierra Leone came from the often violent political jockeying for power between Stevens' Temne people and the Mende. The two groups make up 60 percent of the country's population.

In 1978, Stevens pushed through a nationwide referendum that outlawed the former Mende-based opposition party, the Sierra Leone People's Party, and created a one-party state.

Reminded of this having come to power as an opposition leader, Stevens nevertheless brushed aside the complaints of Sierra Leoneans about the lack of democracy in the country.

"People just don't understand" a multiparty system in Sierra Leone, he replied. Five years ago, Stevens continued, a number of the country's 57 paramount chiefs complained to him "that they were confused by numerous parties," he said.

"There is no word in tribal languages for a loyal opposition," he said. One tribal leader, trying to describe the concept to his peers, Stevens laughed, described an opposition "as a bone caught in" the government's throat.

In a speech following the referendum, Stevens justified one-party rule on the ground that Sierra Leone's competing tribal, ethnic and political tensions brought the country "close to civil war."

Because of Sierra Leone's deteriorating economic situation -- Western creditors were forced to reschedule repayment of $350 million in loans in February -- the International Monetary Fund has been after him to devalue the country's currency, the leone, by 15 percent, Stevens said.

"We devalued by 2 percent last year," Stevens said angrily, "and the traders and other humbugs" doubled their retail prices for consumer goods. "We almost got into [domestic] trouble" because of the higher prices, he said.

Afterward, Stevens said he told IMF officials, "We don't understand this devaluation. You'd beter come and explain it" to Sierra Leoneans, Stevens said he told them.

But even harder times seem to be in store for Sierra Leone. The country's oil import bill has more than doubled since 1978 up to $60 million while its alluvial surface diamond fields, which provide 70 percent of $220 million in government revenue, have begun to dry up. The country also loses about $140 million a year in cross-border diamond smuggling black market activities and corruption.

Underground kimberlite diamond mining would be a major boost to the country's economy, but the government has been unable to raise half of the $60 million required to purchase mining equipment. The other half reportedly would be supplied by the private firm Sierra Leone-Selection Trust, as subsidiary of the DeBeers diamond company of South Africa and a diamond mining partner with the Sierra Leonean government.

A diplomatic source said that Stevens' "very close friend," the influential New York diamond dealer Maurice Templesman, is trying to get financing for Sierra Leone's half of the project witht the aid of Theodore Sorenson, a former adviser for the late president John F. Kennedy. Stevens said he is also seeking help from the oil-rich Persian Gulf country of Kuwait and the European Community.

Mining underground diamonds in Sierra Leone may be lucrative but will "not provide any short-term relief" for the countries economic difficulties, a knowledgable diamond dealer in Freetown said.

"They could begin [the underground mining] five years down the road if they started the project today," the source said. "When it does begin, it will prolong the life of diamond mining here another 25 to 30 years," the source added.