BY NANCY SAN MARTIN

The Cuban government turned the economic clock back a decade Monday with an announcement that it would soon stop accepting the U.S. dollar and instead require the so-called ''convertible'' peso as the only form of payment at businesses across the island.

Economists said the new measures, which take effect Nov. 8, was yet another move in a series of steps in recent months to further consolidate control over the circulation of U.S. currency and raise needed money for the government. Under the new rules, the government keeps 10 percent of all money being coverted.

''This is a move that is following a trend: additional control,'' said Paolo Spadoni, of the University of Florida, who has studied Cuba's economy. ``All the money circulating will go through the government.''

The announcement was made on Cuban television Monday night and came in the form of a resolution adopted by Cuba's Central Bank. Cuban leader Fidel Castro looked on as his chief aide and a television personality read from the document.

Dollars will be changed into convertible pesos at a one-to-one rate with no extra charge until Nov. 8, according to the resolution. But after that, the 10 percent fee will be added to the exchange transactions. The convertible peso is one-to-one to the U.S. dollar, whereas the Cuba peso is worth much less.

GOVERNMENT'S GAIN

In remittances alone, the new 10 percent charge would provide a substantial profit for the government's coffers. Between $400 million and $1 billion is estimated to flow to the island each year in the form of cash transfers from Cuban Americans, primarily from the United States to relatives in Cuba.

''It's going to be very difficult for a lot of people,'' a Havana resident told The Herald by telephone.

''If somebody sends me $100, then I will get $90 back,'' said Jesús, a Havana street merchant. ``Why lose when you have nothing?''

Jesús said he will take advantage of the grace period to trade in the U.S. cash he has saved, but after that, losing 10 percent of his money will feel like ``a punishment for something we haven't done.''

Economists predicted that many Cubans, like Jesús, will flock to stores to stock up on merchandise before the new rule kicks in.

ONLY THE DOLLAR

In his announcement, Castro suggested that Cubans tell their relatives living abroad to send them money in other foreign currencies, such as euros, British sterling or Swiss francs, The Associated Press reported. There will not be a fee to exchange other currencies.

Cuba said the new rule was another necessary response to tightened U.S. restrictions on travel and remittances that limit family visits to the island to once every three years, reduce the per diem that can be spent while on the island and restrict money transfers to immediate relatives.

Soon after the new U.S. measures were announced in May, the Cuban government raised prices at stores that accept dollars by as much as 30 percent.

Last year, Cuba ordered state companies to conduct all of their hard-currency transactions through the central bank, providing more money for the government and enabling more centralized control over state enterprises.

Although only relatively few Cubans are estimated to have direct access to U.S. dollars, U.S. currency has become the backbone of the economy, enabling purchases of higher-quality food, clothing, appliances and other products not readily available at peso-only stores.

VITAL TO ECONOMY

U.S. dollars have been the primary currency in Cuba since 1993, when Castro legalized the dollar amid a grinding economic crisis caused by the Soviet Union's 1991 collapse and the loss of about $5 billion in annual subsidies from Moscow.

The government said the latest measure was tied to the U.S. Federal Reserve's decision in May to fine Switzerland's largest bank for allegedly sending U.S. dollars to Cuba and other nations in violation of U.S. sanctions. The United States implemented an economic embargo against Cuba four decades ago.

Miami Republican Rep. Ileana Ros-Lehtinen said that Castro's announcement was ''a desperate act to change the subject'' from his own failings at home at a time when his fall in Santa Clara last week led to speculation about a future fall from power.

''It's a way for him to shift the blame to the United States,'' Ros-Lehtinen said.

Herald staff writers Jennifer Babson, Pablo Bachelet, Jane Bussey, Gail Epstein Nieves and Matthew Haggman contributed to this report.