Wyoming Pipeline Authority July 22, 2003

Nicor, Inc. $2 billion NYSE market cap Debt is rated “AA” by S&P Corp has several gas-related unregulated ventures in addition to one of the largest gas-only utilities in the country

Nicor Enerchange

History and Formation Originally a joint venture between Nicor Gas, Dynegy, Socal Gas and National Fuel (1993) forming Enerchange, LLC – Nicor bought out Dynegy’s interest in 1998

Nicor Enerchange Enerchange Trading commodity-based services commodity-based services Hub Administration optimization of regulated optimization of regulated assets assets

Enerchange Trading Profile Commodity based wholesale trading company with major focus in the Midwest – Asset-Based Services Balancing Services Storage Services Transportation Services – Risk & Financial Management

Hub Admin Profile Storage and Transportation Optimization agreement with Nicor Gas – Optimize Bcf of storage – Annual throughput approximately 200 Bcf Working on other a similar arrangements with with various third parties Established Front and Back Office

Enerchange Strengths Risk and Financial Management People Assets Midwest Knowledge

Why Pipeline Expansion? Supply – Decreasing Mid-Continent Supplies – Abundant Rockies Supply Demand – Large Mid-Continent Market Demand (IL, IN, MN, MI, WS, and OH) – Continued Market Growth – Mix of baseload industrial demand, power generation load and heat sensitive residential load Pricing – Strong Basis Differentials – Market indicators remain strong

Pipeline Expansion New market for Cheyenne Hub supplies Access to multiple major markets Competitive pricing New long-term supply for mid-continent LDC’s Pipeline contracting party Supply aggregation Scheduling Optimization Balancing Administration Marketing and Trading “Advantages” “Issues”

Nicor’s Proposed Role for the WPA WPA Goals: – Raise price of Wyoming gas relative to Henry Hub – Eliminate infrastructure constraints – Develop Liquid Hubs – Cheyenne Promote liquidity Price Transparency Security of Supply WPA Actions – Aggregate Supply – Provide Back Office Services

Nicor Enerchange’s Role Partner with WPA providing support to their aggregation efforts – Manage Supply Pool – Agent and/or Holder of WPA’s Pipeline Transportation Contracts from the well head to the Mid-Continent – Manage/Optimize Pipeline Capacity – Provide Risk Management Support – Provide Credit Support – Contract Support (invoices, payments, etc.) WPA would pay a minimal flat fee with sharing on optimization and risk management services

Benefits to the WPA Creates a liquid marketplace with pricing based off higher priced markets Allows producers to focus on increasing production not back office activities Provides a central marketplace for Producers Provides Production and Price Transparency Low cost services with sharing arrangement Expedites the development of needed infrastructure in places supported by the WPA

Benefits to Producers Stable pricing linked to higher valued markets Focus will be on E&P efforts not back office issues Low cost services with sharing arrangements that Producers can customize to meet their needs. System that allows Producers to choose their level of participation in pricing and volatility System that eliminates/reduces credit risk System that uses royalty dollars to improve the marketplace System that provides a consolidated outlet to get production to market

The “Nicor Enerchange” Advantage Strong Balance Sheet Service oriented with 11 years experience optimizing natural gas assets Experienced Marketing and Trading staff with established Mid-continent track record Weekly fundamental analysis of the gas market Position reporting Timely and accurate Back Office support for all trading, reporting and collection functions