ITT Corp. today announced a major change in its product marketing strategy to strengthen its position in the rapidly growing European business information market.

ITT officials said that, as part of the new strategy, it will offer customers a flexible package of hardware and software products that incorporates advances in telecommunications and data processing. The products will be sold under the ITT name for the first time instead of those of national ITT subsidiaries in Europe.

The announcement underlined ITT's renewed commitment to Europe, its traditional manufacturing base, following the company's decision last month to abandon attempts to adapt its sophisticated System 12 digital telephone-exchange switch to U.S. standards.

Although it is a New York-based multinational, ITT considers its European credentials to be strong. ITT currently does 90 percent of its telecommunications business in Europe and employs 130,000 people in its European affiliates. "The power and strength of ITT resides in Europe," said Daniel P. Weadock, president of ITT Europe.

ITT officials said their new strategy also is tied to the expected trend of European telecommunications markets away from state monopolies toward freedom for "pan-European" companies to compete across borders.

"We now regard Europe as a single, increasingly coherent market," said Jan Loeber, an ITT vice president. "Like the European Community and many European corporations in the public communications arena, we also are pulling together our European technology."

ITT officials said the new package of products, called "Office 2000," would meet most major international standards and be compatible with the products of other manufacturers. The products will help companies cut costs, for example, by routing data through their telephone exchanges rather than coaxial cable, the officials said.

Company officials said ITT sold $780 million worth of business information systems in Europe in 1985 and expect that figure to reach $1 billion this year. They estimated that the market for business systems would grow from more than $25 billion this year to $45 billion by 1990.

The company's move toward a higher European profile was reflected in the decision to use the ITT name on the Office 2000 products. Company products in Europe currently bear the name of national subsidiaries, such as SEL in West Germany and FACE in Italy.

ITT's decision to close down the System 12 project in the United States, which resulted in a $15 million loss in the fourth quarter, was attributed primarily to a failure to meet booming demand for digital switching equipment. The setback ended ITT's hopes of securing a piece of the U.S. market for digital equipment behind American Telephone and Telegraph Co. and Northern Telecom of Canada, the two dominant suppliers.