Conversion of Series B 8% Preferred Stock Completed.

HERNDON, Va.--(BUSINESS WIRE)--March 16, 1999--PSINet Inc. (NASDAQ:PSIX), the first and largest independent commercial Internet Service Provider (ISP), today announced that all 600,000 shares of its Series B 8% Convertible Preferred Stock have been converted into 3,000,000 shares of common stock. The preferred shares were issued as part of a $30 million private placement that was completed on November 10, 1997. Due to the conversion, PSINet will no longer be required to pay 8% annual dividends, which will result in annual savings of approximately $2.4 million.

The preferred shares were converted by the shareholders after PSINet called the shares for redemption under a provision which permitted the company to redeem the shares once PSINet's common stock had closed for 30 consecutive trading days above $18.00 per share (225% of the 5-day average closing bid price of the common stock at the original issuance of the Series B shares). That threshold was reached at market close on Friday, February 5, 1999.

Headquartered in Herndon, VA, PSINet is a global facilities-based Internet Protocol (IP) data communications carrier focused on the business marketplace. PSINet offers a broad set of high-speed corporate LAN connectivity services supporting managed security and guaranteed Internet, intranet, electronic commerce, Web hosting services, and services for other carriers and ISPs. PSINet operates an international state-of-the-art frame relay and ATM-based, IP-optimized network consisting of more than 500 points of presence (POPs) around the world serving primary markets in Belgium, Canada, France, Germany, Hong Kong, Italy, Japan, the Netherlands, Republic of Korea, Switzerland, the United States, and the United Kingdom. PSINet information can be obtained by e-mail at [e-mail], by accessing the Web site at http://www.psinet.com or by calling toll-free 1-800-799-0676.