CapRock Strengthens Williams Communications' Texas Presence Through $18 Million Agreement.

DALLAS--(BUSINESS WIRE)--July 12, 1999--

In a transaction that will facilitate the rapid construction of its regional fiber-optic network, CapRock Communications Corp. (Nasdaq:CPRK) has entered into a long-term indefeasible right of use (IRU) agreement with Williams Communications Group, Inc., a unit of Williams (NYSE:WMB).

The $18 million agreement provides Williams with co-location and access to 755 route miles of CapRock's network running through Corpus Christi, Harlingen, Houston, Kingsville, Laredo, McAllen and San Antonio.

"CapRock is building a durable, reliable fiber optic network that, when completed, will be the most extensive of its kind in Texas and the surrounding states," said Chip Robertson, CapRock vice president of carrier sales. "Agreements like this are helping to speed the construction of the network, and will allow CapRock to offer state-of-the-art voice, video and data to our customers faster than originally planned."

Williams Communications' nationwide fiber-optic network has 18,600 route miles in service, 20,550 miles of fiber in the ground and plans to complete 32,000 route miles connecting 125 cities by the end of 2000.

About Williams

Williams Communications owns and operates a domestic long-distance fiber-optic network; sells, installs, integrates and maintains business communications equipment in North America; provides data and multimedia satellite transmission globally; and has fiber-optic and wireless interests in Australia and South America. Additional information is available at www.williams.com.

About CapRock

CapRock is a regional facilities-based integrated communications provider (ICP) offering local, long-distance, Internet, data and private line services to business customers. The company also provides switched and dedicated access, regional and international long-distance, private lines and dark fiber to carrier customers. For more information, visit CapRock's Web site at http://www.caprock.com.

Statements contained in this news release regarding expected financial results and other planned events are forward-looking statements, subject to uncertainties and risks. Among many factors that could cause actual results to differ materially from those expected are the following: (a) the substantial indebtedness of the Company including the interest charges associated therewith and the financial covenants imposed upon the Company by such indebtedness; (b) the Company's ability to manage rapid change and its ability to continue the integration of its predecessor companies; (c) supply and demand for data services; (d) the Company's ability to fund the significant capital requirements in order to complete its planned growth including its fiber network; (e) the Company's ability to successfully, timely and cost-effectively complete its fiber network; (f) the development of provisioning, billing, customer service and management information systems; (g) competition in the various segments of the communications industry in which the Company seeks to participate; (h) dependence upon other long distance carriers and local exchange carriers, both as customers and as suppliers; (i) dependence upon key personnel; (j) dependence upon major customers and the risk associated with international customers; (k) the regulation of the Company's industry; (l) possible service interruptions or natural disasters; (m) potential liability of internet service providers; (n) need to obtain and maintain rights of way; (o) compliance with Year 2000 issues; and (p) protection of the Company's intellectual property.