PITTSBURGH — BANKRUPTCIES are increasing at an alarming rate in several key economies around the world.Australia, Britain, and Canada have seen bankruptcy filings rise 50 percent or more within the past year. A Japanese credit-rating agency now expects bad debts related to bankruptcy to reach a record $50 billion in that country - more than triple last year's total. Here in the United States, filings could top 1 million this year - an all-time high and the biggest jump since 1986. "Bankruptcies have gone up dramatically," says Louis Cappelli, senior executive vice president of Sterling National Bank and Trust Company in New York. "The trend has certainly been up over the past several years," says Charles Luckett, an economist at the US Federal Reserve Board. Part of the problem is recession. "We've had an English-speaking recession. And when there's a recession, bankruptcies go up," says David Wyss, research director of DRI/McGraw-Hill economic forecasting firm. Australia, Britain, Canada, and the US have experienced slumps within the past year. Japan's economy has slowed dramatically. But something else is at work - especially here in the US. Bankruptcy filings are rising even in years when there is no recession. Until the mid-1980s, bankruptcies rose sharply during recessions and rose slowly or declined during expansions. They tend to rise near the end of recessions because it takes time for delinquent bills to catch up with companies and individuals. That pattern was broken in 1985, when US bankruptcy filings jumped 18.3 percent, followed by a 28.5 percent jump in 1986. Both were years of healthy economic growth. The rate of increase slackened for the rest of the 1980s but reached 15 percent last year. If, as expected, the number of filings tops 1 million, 1991 could equal or exceed the 1986 increase. The postwar record was set in 1975, when filings jumped 34.3 percent. The record this century was 68 percent, set in 1921. "The root cause of all this is too much debt ... and that has grown dramatically in the 1980s," says Sam Gerdano, executive director of the American Bankruptcy Institute. In 1980, the average American had 65 cents worth of debt for every $1 of income; last year, the debt level had risen to 83 cents. Another reason for the bankruptcy increase: Changes in federal and state bankruptcy laws have made it easier for companies and individuals to file and to protect more of their assets. Also, bankruptcy is becoming socially acceptable. "There is less stigma attached to bankruptcy than there once was," says Mr. Luckett of the Federal Reserve. High-profile figures such as Donald Trump and several Hollywood stars have filed for protection from creditors. So ordinary people are filing in droves. For example, the National Foundation for Consumer Credit is opening four new offices a week in the US to keep up with the demand for credit counseling. Chicago bankruptcy attorney Marc Shuger says he gets 70 to 80 calls a day from people asking for advice about their credit problems. He sells a video cassette on how to file for bankruptcy. Other companies are selling books and self-help aids on the subject. The American Bankers Association and other groups are so concerned about the rise in personal bankruptcies that they are pushing Congress to tighten up the code. "We are trying to discourage the practice, except as a last resort," says Virginia Stafford, spokeswoman for the American Bankers Association. Mr. Shuger sees another culprit. He blames credit companies for lending money so easily. Some of his clients get home mortgages and credit cards within a year of filing for bankruptcy. The bigger threat to the economy comes from business bankruptcies. Highly leveraged buyouts and failing real estate developments have forced many companies to file for bankruptcy. Through the first half of 1991, business bankruptcies were running 50 percent above the totals for the same period last year, according to Dun & Bradstreet Corporation. Economists expect the trend to continue through the rest of the year. But, for now, they are not too worried. "I don't see it significantly impacting the economy," says Mr. Cappelli of Sterling National Bank.