CAIS Internet Comments On Microsoft Closing.

Business Editors/Hi-Tech Writers

WASHINGTON--(BUSINESS WIRE)--Aug. 4, 2000

CAIS Internet (Nasdaq"CAIS") today announced the closing of a previously announced $40 million cash investment by Microsoft Corp. in newly issued shares of CAIS convertible preferred stock.

CAIS and Microsoft have been working together on several strategic initiatives including the development of a co-branded MSN portal that will distribute Internet content via CAIS's broadband networks in the hospitality industry, with an option for Microsoft to participate with CAIS in multifamily dwelling unit industries.

We will further highlight our company's performance in conjunction the issuance of our second quarter financial results after the market closes on Monday, August 7th.

About CAIS Internet

CAIS Internet, Inc. (Nasdaq:CAIS) is a leading broadband access solutions company. CAIS provides the mobile workforce with comprehensive high speed Internet solutions while at home in apartments, at work during the day in small-to-medium businesses, or on-the-go at airports, travel plazas, cruise ships, retail stores, and in hotel guest and meeting rooms.

Whether it's creating a low cost in-building network and content service for multiple users with proprietary and patented technologies, providing a public area Internet kiosk, or giving businesses daytime connectivity with DSL & leased-line dedicated access, the company delivers a cost-effective, easy and convenient Internet experience for customers.

The customer experience is the result of a one-stop, integrated solutions package of innovative CAIS network access and technologies, IPORT software, customer support, portal content and systems.