SUPPLEMENTAL AGREEMENT


The undersigned, NUI Corporation, AGL Resources Inc. and its wholly owned
subsidiary, Cougar Corporation, are each party to an Agreement and Plan of
Merger, dated July 14, 2004 (the "Merger Agreement"), pursuant to which AGL
Resources has agreed to purchase all of the outstanding shares of NUI
Corporation on the terms described therein (the "Transaction"). Capitalized
terms used and not otherwise defined herein shall have the respective meanings
given to such terms in the Merger Agreement.

WHEREAS, Article 6 of the Merger Agreement sets forth certain conditions to the
parties closing the Transaction, including but not limited to the Required
Consents being obtained and the Required Consents becoming Final Orders;

WHEREAS, the Merger Agreement defines the consent of the Florida Public Service
Commission ("FPSC") as a Required Consent;

WHEREAS, each of the undersigned has agreed that the receipt of a Required
Consent from the FPSC is not in fact a legal requirement for the consummation of
the Transaction;

NOW THEREFORE, for the premises and covenants provided herein the undersigned
hereby agree as follows:

(1)    AGL Resources and Cougar Corporation agree that for purposes of
       determining whether the conditions required to be fulfilled to close the
       Transaction set forth in Sections 6.1(d), 6.2(b) and 6.2(c) of the Merger
       Agreement have been satisfied, each of AGL Resources and Cougar
       Corporation hereby waives the condition required to be fulfilled to close
       the Transaction with respect to obtaining a Required Consent from the
       FPSC under the terms and conditions of Sections 6.1(d), 6.2(b) and 6.2(c)
       of the Merger Agreement.

(2)    NUI Corporation agrees that for purposes of determining whether the
       conditions required to be fulfilled to close the Transaction set forth in
       Section 6.1(d) of the Merger Agreement have been satisfied, it hereby
       waives the condition required to be fulfilled to close the Transaction
       with respect to obtaining a Required Consent from the FPSC under the
       terms and conditions of Section 6.1(d) of the Merger Agreement.

The undersigned agree that any agreement or waiver expressed herein does not
constitute or imply an agreement or waiver of any other condition or term of the



Merger Agreement, including, but not limited to, those expressed in Section
6.2(d) of such agreement. This agreement shall not be amended, modified,
rescinded or revoked in any way, except through the express written agreement of
each of the undersigned.




IN WITNESS WHEREOF, the parties have executed this supplemental agreement as of
the 23rd day of September, 2004


NUI CORPORATION

/s/ Steven D. Overly
-----------------------------
Steven D. Overly
Vice President, Chief Financial Officer, General Counsel and Secretary


AGL RESOURCES INC.

/s/ Richard O'Brien
--------------------------------
Richard O'Brien
Executive Vice President and CFO


COUGAR CORPORATION

/s/ Richard O'Brien
--------------------------------
Richard O'Brien
Executive Vice President and CFO