3333 Warrenville Road

Suite 300

Lisle, IL 60532

Phone 630 245-7800

Fax 630 245-7835

Internet www.cvgasstorage.com

Central Valley Gas Storage, L.L.C

Non-Binding Open Season

October 12, 2009

Dear Prospective Central Valley Customer:

Central Valley Gas Storage, LLC, (“Central Valley”) a subsidiary of Nicor Inc., is soliciting non-binding bid proposals from interested parties for storage capacity in a natural gas storage facility currently under development in the Sacramento River Valley of north central California.

Central Valley filed for a Certificate of Public Convenience and Necessity with the California Public Utility Commission in August, 2009 and expects to provide firm storage services by April, 2012. The Central Valley gas storage project has filed for a total working capacity of 8.0 Bcf when fully developed and will interconnect with the gas transmission system of Pacific Gas and Electric Company near the Delevan compressor station.

After further extensive review of the field reservoir characteristics, Central Valley is adding two new service profiles to the three turn service previously offered in an open season held in May of 2008. In addition to a slightly modified three turn service offering, Central Valley has designed additional services setting forth options that approximate two and four turn service profiles. These new services will be provided under the Central Valley pro forma Firm Rate Schedule set forth in the gas tariff currently on file with the CPUC. Proposals submitted by prospective customers will be evaluated by Central Valley and ranked based on a review of available services within each service offered and in total working capacity available for the project. If prospective customers are interested in more than one service profile offered, multiple bids will be accepted and reviewed independently. Individual bid forms for each of the three service profiles are included for your use. Upon the close of the open season, Central Valley will contact the successful bidders in order to proceed with negotiation of binding Precedent Agreements. A draft of the Precedent Agreement has also been included for your review.

The non-binding open season begins immediately and will continue until Thursday November 12th, 2009. If you are interested in contracting for firm natural gas storage service, please submit the attached non-binding bid forms by 5:00 p.m. Central Standard Time on November 12th, 2009. Please fax, e-mail or send your bid response to me at the following address:

John Fortman

Central Valley Gas Storage, LLC

3333 Warrenville Road, Suite 300

Lisle, Illinois 60532

e-mail -

fax - (630) 245-7835

Central Valley Gas Storage, L.L.C

Non-Binding Open Season

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Additionally, if you have any questions related to the Central Valley project, please contact me at (630) 245-7845 or Oscar Towne at (630) 245-7814.

Yours truly,

John Fortman

Manager

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