AboveNet Enters 2nd Year as Provider of Secure Private Fiber Optic Network to Northern Trust

Leading Financial Institution Continues to Reap the Benefits of Private Fiber Network

NEW YORK, April 20, 2004 - AboveNet, Inc., the top provider of integrated access services to leading edge enterprises for premium networking power, entered its second year as the provider of Northern Trust’s private fiber optic network. The leading financial institution continues to see the benefits of the secure fiber optic network that allows it to by-pass the local switched area network and lease a redundant, unshared network in the Chicago market.

Northern Trust originally leased the fiber optic network from AboveNet in 2002. The Company needed a means to connect its facilities but wanted a more secure and cost-effective infrastructure than the traditional telecommunication companies could provide. AboveNet’s extensive metropolitan area network, combined with its value and security proposition that allows customers to lease whole strands of fiber for private use, made it a great choice for the growing financial company.

“We were concerned with having our entire infrastructure on the public network and were looking for a means of securing our network, while still maintaining control over the cost and performance, said William Jarrett, Sr. Vice President, Network Services of Northern Trust. “AboveNet allows us to remain in control of our network while decreasing our cost and increasing the security of our data. We have felt more secure over the past two years knowing that our data, which is so valuable to our company, is traveling a private and diverse route.”

“AboveNet is a valuable alternative to customers looking for a secure, high-speed network environment,” said Bill LaPerch, president and chief executive officer, AboveNet. “Our services provide enterprises, like Northern Trust, with an infrastructure that is uniquely their own in terms of control, performance, route and protocol. We are very proud of our longtime relationships with our fiber customers.”

About Northern Trust
The Northern Trust Company (www.northerntrust.com) is the principal subsidiary of Northern Trust Corporation (NASDAQ: NTRS), a multi-bank holding company with worldwide locations, and is a leading provider of global custody, asset administration, and investment management services for institutions and individuals. As of 31 December 2003, Northern Trust had USD 2.2 trillion in assets under custody and USD 478.6 billion in assets under management. Northern Trust is headquartered in Chicago USA, with other international offices in London, Dublin, Hong Kong, Singapore, Toronto, and New York.

About AboveNet, Inc.
AboveNet, Inc. is the top provider of integrated access services for leading edge enterprises. AboveNet builds and operates an office-to-office, 100-percent optical network enabling customers to create an efficient, cost-effective network that breaks economic and performance barriers imposed in the last mile by complex legacy telecom infrastructures. With one of the most extensive metropolitan optical network in the world, data centers throughout the US and Europe, top quality managed services and a high-performance IP network, AboveNet is able to offer the most flexible and complete information exchange solutions in the industry.

This news release contains forward-looking statements that involve risks and uncertainties. Factors that could cause or contribute to such risks and uncertainties include, but are not limited to, general economic and business conditions, competition, changes in technology and methods of marketing, and various other factors beyond the Company's control. This also includes such factors as are described from time to time in the SEC reports filed by the Company including the most recently filed Forms S-3, 10-K, 10-Q and 8-K-.