A rash of bad economic news this summer for West Germany has dashed hopes of an upturn this year and carries unsettling consequences for Chancellor Helmut Schmidt, his nation's patience and Western alliance harmony.

The failure earlier this month of West Germany's second-largest electronics company, the sputtering of the country's export drive and the rapid growth of unemployment all point to an economy more chronically ill than officials in Bonn had been ready to concede. They also belie recent optimistic forecasts by outside analysts such as those at the Organization for Economic Cooperation and Development.

As West Germany now heads into its third year of stagnation, there is a growing realization that the nation's economic erosion extends further than first imagined. A second-wind spurt toward recovery, like the one that lifted West Germany out of its mid-1970s slump, does not appear to be on the horizon.

For Europe, this sadly shreds expectations that the region's biggest and historically most vigorous economy would spring back to life and pull its neighbors' sluggish economies along. For the United States, a weakened West German economy likely means more resistance to entreaties for higher allied defense spending and to pleas for fewer business deals with the Soviets.

Here on the home front, a gloomier outlook threatens to encourage more of the same frictions -- between governing coalition partners, Germans and foreign workers, environmentalists and business interests -- that already have provided a fitful picture of this country adjusting to lower expectations after decades of growth and prosperity.

Most ominous is the slowing of export sales, which in past recessions have been the flywheel that kept West Germany's economic engine turning.

The falloff in foreign orders is being blamed on weakening demand from developing and oil-exporting countries and continued sluggish economic activity in Western industrial countries. But there is a quiet acknowledgement that West Germany's aging industry is losing its competitive edge in some old key fields and failing to establish itself in the new frontiers of computer and microelectronic technology.

Leading forecasters here are predicting that the country will fall far short of the government's ambitious 3 percent growth target next year.

Unemployment -- at 1.75 million people or 7.2 percent of the work force, already the highest level since the Federal Republic was created 37 years ago -- is rising faster here than in any other major industrialized nation. Corporate bankruptcies, too, are at a record level, running 50 percent ahead of last year's number.

But not until the recent financial collapse of the electrical giant AEG-Telefunken did the gloomy figures seem to sink in. The company is a household name in appliances and was formerly a prime source of goods from televisions to turbines contributing to Germany's post-World War II reconstruction.

Declaring itself insolvent, AEG has begun court settlement proceedings asking that 60 percent of the $1.8 billion debt of its parent company be written off. Much of this is owed to West German banks.

"When even enterprises in such dimensions can't survive," observed the authoritative weekly newspaper Die Zeit last week, "then it dawns on people that the economic crisis is more than a passing irritation, more than just one of the many bad news items on the evening news show. Suddenly, the mood turns bad."

The prolonged recession has exposed structural problems in the economy, suggesting that the slump cannot be brushed off simply as a result of weak world demand or high U.S. interest rates.

One of the secrets of the postwar industrial resurgence here was the purchase of foreign, mainly U.S., technology that was applied with characteristic attention to detail both in design and marketing. That strategy is difficult to repeat now.

According to figures from the Institute for World Economy in Kiel, West German manufacturers have lost a share of the world market during the past decade in such central areas as chemicals, engineering products and transportation equipment.

More now depends on homemade innovation, but here things also look disappointing. Excursions into computer technology here -- AEG was among those that ventured -- have not been very successful.

The country's nuclear power industry faces tough political opposition from the invigorated new national Green Party of environmentalists. Except for Siemens, which leads the German electronics industry, German firms lag well behind the Americans and Japanese in microchip technology.

An aversion to risk-taking and a rigid industrial structure dominated by big firms and their conservative bankers often are cited as the reasons why the West Germans are scoring few breakthroughs.

Business confidence, tentative before, has dropped in recent months as doubts about Bonn's political course have risen. Capital investments are being delayed.

Schmidt continues to blame high U.S. interest rates for forcing German rates up and thereby discouraging business spending here. But the fact is, the wage cost of doing business in West Germany -- higher than in any other Western country after Belgium, Sweden and Norway -- is itself a barrier to profitability.

In its June report, West Germany's Federal Bank took special note of the fact that substantial amounts of long-term funds have been flowing out of the country this year, going largely to the United States.

Not all the economic reports are bleak. The West German inflation rate, low to begin with, is dropping. Wage hikes have been moderate. Productivity is rising in the recession. Corporate profitability, after falling 25 percent in two years, is recovering.

But the certainty of increasing prosperity for the Germans is no longer there, and with that, the country's old postwar political equations are not holding so neatly.

The prospect of continued stagnation could tear the thin adhesive of a federal budget compromise that patched the Bonn coalition together just before the summer recess. Already Schmidt and his coalition partner, Hans-Dietrich Genscher of the Free Democratic Party, express different views on how to make up the shortfall in revenues expected in view of new pessimistic forecasts.

Schmidt spoke during the weekend of going for "possibly somewhat higher" borrowing, while the thrifty Genscher challenged Schmidt's party to think instead about swallowing more cuts.

Another showdown is anticipated following crucial September elections in the state of Hesse -- the home, it so happens, of AEG's corporate headquarters.