The United States, Canada and Britain have warned their citizens against traveling to Guyana until political unrest that began after Dec. 15 general elections ends.

One local business leader said the travel advisories have forced foreign partners and new business interests to postpone indefinitely their visits to Guyana, which had been scheduled for immediately after the election.''The country and domestic business has suffered because of the political turmoil we have experienced,'' said the business leader, who asked not to be named.

The South American nation, which has attracted major investments in its mining and forestry sectors and for its privatization program, has been hit by demonstrations and marches since election results were declared.

The main opposition People's National Congress has accused the ruling People's Progressive Party of retaining office through fraud. The PPP at weekend agreed to an audit of the votes cast in the election, and to new elections in two years.

The parties also agreed at the weekend - upon intervention by a team from the Caribbean Common Market of which Guyana is a member - to end the demonstrations and marches.

Guyana's Private Sector Commission said businesses have been hard hit by the unrest. The manufacturing and distribution sectors, transportation and other services have suffered from the shutdown of stores, offices and factories, the commission said.

''The events taking place daily in the city and city center continue to drive businesses downwards,'' the commission said in a statement issued just before the parties reached agreement.

''These occurrences are sending ripples overseas which could lead to a destruction of the favorable business climate Guyana has earned over the past five years, that may never be regained,'' it said.

The economy, which is based on agriculture (rice and sugar) and on mining (gold and bauxite), expanded by an estimated 7 percent last year, following expansion of 7.9 percent in 1996 and 5.1 percent in 1995.

The mining sector and sugar production were only marginally affected by the month of unrest, officials said.

The English speaking republic in northeastern South America will need several months of image building to recover its economic momentum, business leaders and officials said. Officials have vowed to increase efforts to attract foreign business to Guyana and to restore business confidence.

''We will continue with our economic diplomacy drive, which is to sell Guyana overseas as an investment friendly country, a country where eco-tourism has great potential and where the local private sector is prepared to work with foreign investors in partnerships,'' said Clement Rohee, the foreign minister.