MCI WorldCom in Europe delivers full corporate data communications portfolio over a single service

Launch of ATM Plus enables customers to implement Internet
Protocol networking strategies today

London, 26 April 1999 - MCI WorldCom today unveiled ATM Plus, a
data networking service based on the industry leading Asynchronous
Transfer Mode (ATM) communications technology. The service combines MCI
WorldCom's existing international ATM service with managed
equipment in the customer's premises to provide local area
performance over the wide area network. The new service dramatically
reduces the cost of ownership associated with wide area corporate
networking and bridges the gap between legacy technologies and the next
generation networking environment. Among other forms of advanced
connectivity, the new service allows businesses to implement Internet
Protocol (IP) corporate networking strategies today. MCI WorldCom
estimates the cost of implementing ATM enabled connectivity with
in-house equipment and network integration resources to be as much as
twice that of the ATM Plus service.

The service is available in and between the UK, France, Germany, the
Netherlands, Belgium, Sweden and Switzerland and will be extended to
MCI WorldCom's other key geographic markets by the end of 1999.

MCI WorldCom's ATM Plus service is based on a multi technology
platform that delivers both native ATM and legacy LAN connectivity. ATM
Plus can deliver a full telecom portfolio, including private line, high
speed data, PBX to PBX networking, and internet protocol as a single,
managed scaleable service. By segmenting different IP applications into
virtual LANs (VLANs), and associating these VLANs with specific ATM
Service Classes, ATM Plus allows customers to implement IP networking
strategies today.

The ATM Plus portfolio of services is delivered via a managed ATM
'edge' device supplied, configured, supported and managed by
MCI WorldCom. In combination with the high speed core network, this
allows MCI WorldCom to seamlessly deliver local area performance over
the wide area, effectively breaking the traditional LAN/WAN
demarcation.

Liam Strong, CEO, MCI WorldCom International, explains,
"Business customers are currently faced with a real dilemma when
selecting the right strategy for networking technologies. There is a
huge amount of momentum behind IP. However, in their current inception,
standards based IP networks can not deliver the speed, reliability and
quality of service that corporations demand. Our ATM Plus service,
based upon our global high bandwidth network, will provide a guaranteed
quality of service for IP networking now."

With ATM Plus, bandwidth and service type can be provisioned to suit
initial customer demands and readily upgraded as the customers
requirements evolve, helping businesses to simplify corporate
networking whilst remaining flexible and scaleable. By providing a cost
effective, managed service, ATM Plus frees customer IT and networking
resources to focus on the applications that deliver strategic
advantage.

"ATM Plus will enable customers to take advantage of the cost
benefits delivered by consolidating multiple services into a single ATM
service delivery. The service is highly scaleable, allowing customers
to start small and grow big, mixing and matching LAN and ATM
technologies along the way," said Liam Strong. "By providing
a managed network infrastructure, the ATM Plus service allows customers
to dedicate more resources to desktop applications. It is these desktop
applications, focused on the enterprise core business, that ultimately
provide the competitive advantage."

ATM Plus is based on MCI WorldCom's international Asynchronous
Transfer Mode (ATM) service. Unlike any other international service on
the market, the MCI WorldCom service provides full ATM functionality at
bandwidths between 2Mbps and 45 Mbps with a common feature set, over a
common technology platform with full end to end management and
control.

Notes to Editors

ATM Technology allows customers to consolidate different traffic
types onto a single backbone network platform. MCI WorldCom's ATM
service can be configured to optimise transmission costs to traffic
type. A customer can order a single ATM service capable of supporting
all or any of the following:

Constant Bit Rate (CBR) where the customer is guaranteed delivery of
the bandwidth contracted for. This provides a solution for customers
requiring high performance of specific capacity circuits between 1Mbps
and 8Mbs and is ideally suited to enable customers to integrate
critical and time sensitive applications such as video within the
corporate data network.

Variable Bit Rate (VBR) where the customer is guaranteed a sustained
bit rate but is able to burst to predetermined limits to meet peak
traffic demands. VBR provides corporate customers with a solution to
the need to grow capacity on existing data networks where fast response
times are critical.

Available Bit Rate (ABR) where the customer does not receive a
guaranteed bit rate but is assured an average number of bits are
transferred over a given period of time. This provides customers with a
cost effective solution to non-delay and non-time sensitive
applications such as file transfer and email.

The service combining the three service types would provide a
customer with a single, consolidated and managed backbone carrying
traditional data, IP and video traffic between on net sites throughout
Europe.

MCI WorldCom

MCI WorldCom is a global communications company with revenue of more
than $30 billion and established operations in over 65 countries
encompassing the Americas, Europe and the Asia-Pacific regions. MCI
WorldCom is a premier provider of facilities-based and fully integrated
local, long distance, international and Internet services. MCI
WorldCom's global networks, including its state-of-the-art
pan-European network and transoceanic cable systems, provide end-to-end
high-capacity connectivity to more than 40,000 buildings worldwide.

For more information on MCI WorldCom, visit the World Wide Web at
www.wcom.com.