MOSCOW, FEB. 12 -- Soviet Prime Minister Valentin Pavlov claimed today to have thwarted a plan involving unnamed Western and Soviet banks to overthrow President Mikhail Gorbachev and restore capitalism.

In an interview with the official labor daily Trud, Pavlov said the plotters had hoped to create a "financial catastrophe" in the Soviet Union by flooding the country with worthless rubles. He said "advocates of instant privatization" would have taken advantage of hyperinflation to seize power and sell the country out to the West.

"Such operations are conducted in many regions of the world when someone wants to change the political system or overthrow unwanted political leaders. Someone simply decided that President Gorbachev had become a nuisance and had to be removed," said Pavlov, claiming that the plans had been foiled thanks to his controversial decision last month to withdraw high-denomination 50- and 100-ruble notes from circulation.

Pavlov, who was promoted last month to succeed Nikolai Ryzkhov, provided no evidence to support his allegations, which echo the propaganda line taken by sections of the Communist-controlled media. He said his position obliged him to keep silent on important details, adding that the "financial war" against the Soviet Union is continuing.

The interview appeared largely aimed at an unsophisticated Soviet audience, indoctrinated for many years with the idea that "imperialist forces" in the West are trying to destroy the socialist system. Gorbachev's spokesman, Vitaly Ignatenko, later played down the idea of a coup, saying he doubted such an operation would work.

Western bankers in Moscow discounted Pavlov's claims of an elaborate conspiracy to destroy the Soviet economy by encouraging hyperinflation. They conceded, however, that the country's chaotic economic system and the lack of coordination between the central government and its 15 constituent republics had created opportunities for all kinds of financial swindles.

"There's a complete lack of knowledge here about how the real world works. Lots of people are trying to make a quick buck, but I don't think there's any sinister plot," said a Western banker who requested anonymity.

In the most sensational incident so far, a British citizen was arrested at Moscow airport last month with an IOU for goods worth 140 billion rubles from a Russian trading company. Russian government officials involved in the case have accused the Soviet secret police, the KGB, of setting them up.

Pavlov's main purpose in the interview appeared to be an attempt to justify the disruption to the Soviet economy caused by last month's recall of high-denomination bills, which was presented as a move against black marketeers. It was also said to be an attempt to shore up the purchasing power of the ruble and soak up excess money in circulation. For the past three years, the government had printed rubles at a rate unmatched by growth in the supply of food or consumer goods.

Many Soviet economists criticized the operation, arguing that it helped destroy any remaining public confidence in the ruble without balancing the consumer market.

According to official statistics, the government succeeded in removing 8 billion rubles in unreturned bills from circulation.

In the interview with Trud, Pavlov described the exchange of high-denomination bank notes as a "defensive measure" designed to forestall a massive injection of money into the Soviet Union from the West. He said the attempt involved laundering billions of Soviet rubles "through Germany to Switzerland and through Hungary to Luxembourg and the Netherlands."

Asked what would have happened if the Western banks had succeeded in carrying out such a plan, Pavlov replied: "It would have caused a financial disaster. Pensioners and invalids would have been able to buy a box of matches with their 100 rubles. We would have all become millionaires, as was the case in 1918 when one could not buy a needle for a million.

"I should say once again that this campaign is continuing. I can assure you that not only days, but even hours were important in that matter. We had to keep everything secret and act as best we could. History will judge us," Pavlov said.

A 53-year-old professional economist and former finance minister, Pavlov is generally considered to be a very intelligent bureaucrat more interested in making the system of central planning work effectively than in radical economic reform. Less rigid economists have accused him of waging a successful campaign to persuade Gorbachev not to adopt market-oriented reforms in the near future.

In his interview with Trud, Pavlov said the government is planning a series of measures to stabilize the ruble in hopes of making it at least partly convertible against Western currencies. Officially, the ruble is worth $1.60, but it trades for less than 5 cents on the black market.

Pavlov gave few details about his proposed reforms but said the Soviet Union might draw "on the experience of China to some extent." China has two currencies operating alongside each other -- a soft yuan used by the local population on a daily basis and special foreign exchange certificates that provide access to a chain of stores selling luxury items and Western consumer goods.