Europe's business community shuts up shop in August and heads for the beaches.

But this year, more executives have stayed at their desks to manage a rising tide of investment and record cross-border mergers and acquisitions.In the past week, Britain landed a 1 billion-pound ($1.6 billion) investment by Siemens of Germany in a microchip plant and a UK20 million expansion by Makita of Japan to triple its manufacture of power tools. The week before, Sumitomo Rubber unveiled a UK6 million investment at a plant in Birmingham in the English Midlands.

These spending plans are part of an accelerating investment boom that has officially buried the recent recession, the deepest in a generation.

Spending by European companies alone on new plants, machinery and buildings will rise by 13 percent this year, a sharp revision from an earlier forecast of 9 percent growth, according to a survey by the European

Commission. This returns the EU to a rate of growth not seen since 1992.

The survey, of 23,000 businesses in 12 EU nations, showed that the business community is most bullish in the Netherlands, Spain and Italy, followed by Britain and Denmark.

Meanwhile, cross-border merger and acquisition activity is breaking all records, underlying the business community's efforts to create pan- European groups to exploit the single market that was launched in January 1993.

European M&As scaled $75.5 billion in the first six months of the year, according to IFR Securities Data. Activity was dominated by an all- British pharmaceuticals deal, Glaxo Holdings' UK9 billion ($14.4 billion) takeover of Wellcome. An unusually large number of deals involving banks and insurance companies, including the $3 billion purchase by Allianz, the German insurer, of Vereinte-Magdeberger from Swiss Re, also helped to smash records.

The bonanza, however, has bypassed Europe's two biggest economies, Germany and France, where business confidence has slumped sharply since the beginning of the year, according to the European commission's investment survey.

German businessmen complain that are being victimized by the strength of the deutsche mark compared with the currencies of their British, Italian and Spanish rivals. They have been joined by the French who claim their competitors have engineered currency devaluations to sharpen their competitive edge. The Italian lira has slumped by 35 percent against the mark since mid-1992, and the pound sterling and Spanish peseta are down by 20 percent to 25 percent.

Almost every blue chip German company has issued warnings in the past three months that the strong mark will depress 1995 earnings, shut off export markets and hasten the transfer of production facilities abroad. Siemens' decision to build its $1.6 billion chip plant in Britain rather than neighboring Austria partly reflected the difference between the weak pound and the strong Austrian schilling.

Currency-related losses are mounting: an estimated $140 million in 1995 at Lufthansa, Germany's national airline and nearly $340 million at Danone, the French food concern, in the first half of the year. Adam Opel, General Motors' German unit, says its 1995 profits would be 1.1 billion marks ($785 million) higher if 1991 exchange rates had been maintained.

Daimler-Benz, Germany's biggest industrial conglomerate, warned of severe losses for 1995, probably over $2 billion, largely due to the fact that Dasa, its aerospace unit, operates in a market dominated by the weak dollar.

German industry has been indulging in an unprecedented bout of angst. The Association of the Chambers of Commerce says "the international competitiveness of German companies is in danger." Even more alarming, the Metal Industry Employers' Federation warns of "the destruction of Germany as an industrial base."

Helmut Werner, chairman of luxury-car maker Mercedes-Benz, has called for political action to stabilize European exchange rates. French business is making noises about trade protection against imports from cheap currency EU countries.

German economists say businessmen are being unduly pessimistic about the impact of a hard mark, ignoring the upside including sharply lower raw material costs. Ifo, the respected Munich-based research group, says the economy will grow by 2.5 percent in 1995 and 1996, just below its expansion in 1994.

And the Bundesbank may provide a fillip Thursday when it returns from its summer recess to decide what to do about its key interest rates.