In the span of less than an hour Thursday, China's central bank and the European Central Bank (ECB) cut interest rates and the Bank of England stepped up its economic stimulus program.

While the moves were not coordinated, they emphasize the concern financial officials have about a global economic slowdown and highlight the role central banks are playing in seeking to bolster growth.

China's central bank, the People's Bank of China, unexpectedly cut regulated bank lending rates by nearly a third of a percentage point and made a rule change that could reduce borrowing rates for companies with good credit by an additional three-fifths of a percentage point.

Just four weeks earlier, the central bank announced a similar rate reduction and rule change. The moves underline the growing worries in Beijing about what the government has begun to describe as a sharp economic slowdown.

In Frankfurt, Germany, the ECB cut its benchmark interest rate to its lowest level, from 1 percent to 0.75 percent, in what may be its most aggressive move yet to unblock the flow of credit and prevent further deterioration of the eurozone crisis.

Most analysts expected a cut, but investors looking for a more aggressive move were disappointed and major stock indexes in France, Germany and Italy fell sharply.

With interest rates now close to zero, the ECB and its president, Mario Draghi, will have fewer conventional monetary policy tools available to combat the crisis.

In London, the Bank of England announced an increased bond-buying program intended to stimulate the struggling British economy out of a double-dip recession. It left Britain's benchmark interest rate unchanged at a record low of 0.5 percent.

In Beijing, the central bank reduced the regulated rate for one-year bank loans by 0.31 percentage points, to 6 percent.

At the same time, it said banks would be allowed to charge as little as 70 percent of the regulated interest rate to good customers; the previous minimum, set a month ago, had been 80 percent. And until the initial rule change early last month, banks had been required to charge at least 90 percent of the regulated rate, even to their best customers.

On Thursday, the central bank also lowered the regulated minimum interest rate that banks must pay depositors. But the reduction was only a quarter of a percentage point, a sign that Chinese banks are struggling to persuade Chinese households and companies to deposit more money. Savers have turned to a variety of trusts and other investment vehicles rather than accept the very low regulated deposit rates, which Thursday's changes will drop to a minimum of 3 percent for one-year certificates of deposit.

China's central bank did not explain its moves, which take effect Friday. But the initial reaction of private sector economists was that the rate cuts signal genuine worry among Chinese decisionmakers.

"This aggressive policy action reflects, in our view, a deepening concern by policymakers that the economy has yet to find a bottom and requires additional stimulative monetary settings to engineer a recovery," Nick Chamie, an economist at RBC Dominion Securities, wrote in a research note.

Few economists worry that the Chinese economy will stay weak if its government decides to mount a sustained stimulus effort. Much of the current slowdown in China is the result of the government's hitting the brakes too hard last year, through a national credit squeeze engineered to slow inflation and a series of bans on real estate speculation to make housing more affordable.

European officials face a greater concern about growth.

The ECB's president, Draghi, said Thursday's interest rate decision was based on indications that growth in all 17 of the eurozone countries had shown signs of slowing. But he sounded upbeat about the potential long-term benefits of steps agreed to by the bank and E.U. leaders last week to address underlying causes of the region's debt crisis.

"We welcome the move to take action to address financial market tensions, restore confidence and revive growth," Draghi said of the leaders' plans, which would include giving the ECB a new role as a centralized supervisor of the region's banks to ensure more financial discipline.

The interest-rate cut is likely to increase speculation that the central bank's next step will be huge purchases of government bonds, similar to the quantitative easing undertaken by the Federal Reserve.

"The ECB is aware that cutting rates to their lower bounds is likely to fuel market expectations that an outright Q.E. launch will follow shortly after," Jens Sondergaard, an analyst at Nomura, said in a note to clients ahead of the rate decision.

The ECB also cut the rate it pays on deposits to 0 percent, a record low, in hopes of discouraging banks from hoarding cash. But banks reluctant to risk loaning extra cash may simply opt to keep the money in their own vaults now that there is no incentive to deposit it with the ECB.

Britain's decision to add 50 billion pounds ($78 billion) in additional stimulus comes on top of 325 billion pounds already pumped into the economy by the Bank of England over the past several years.

Britain's banking crisis prompted London to embark on its biggest austerity program since World War II. The economic outlook has been worsened by the crisis in the eurozone economy, which has sapped global confidence and decreased demand in major trading partners.

George Buckley, chief British economist at Deutsche Bank in London, said the impact of the new spending would be equivalent to adding 0.5 percent to gross domestic product.

But he cautioned that the overall impact on the economy would be limited, given the difficulties confronting other European economies.

"This is helpful at the margins, but the big issue is what happens to the European economy as that will be transmitted across the English Channel," he said. "Fifty billion pounds in quantitative easing is not going to solve the problems. All the Bank of England can hope to do is to offset some of the headwinds from Europe."