NiSource Prices Offer of $500 Million in Two Series of Notes

MERRILLVILLE, Ind., Nov. 14, 2011 /PRNewswire/ — NiSource Inc. (NYSE: NI) today
announced that its finance subsidiary, NiSource Finance Corp., has priced a
public offering of $250 million aggregate principal amount of 4.45% notes that
will mature on December 1, 2021 and $250 million aggregate principal amount of
5.80% notes that will mature on February 1, 2042. NiSource Inc. will fully and
unconditionally guarantee NiSource Finance’s obligations under both series of
notes.

NiSource Finance intends to use the net proceeds from the sale of the 4.45%
Notes due 2021 to contribute to the pension plans of NiSource Inc. and certain
of its subsidiaries and the net proceeds from the sale of the 5.80% Notes due
2042 to fund a portion of the purchase price for the cash tender offers
announced earlier today.

This news release is neither an offer to sell, a solicitation to buy nor an
offer to purchase or sell any securities. Barclays Capital Inc., Citigroup Group
Global Markets Inc. and J.P. Morgan Securities LLC are acting as joint
book-running managers for the offering. BNP Paribas Securities Corp., Deutsche
Bank Securities Inc. and Scotia Capital (USA) Inc. are acting as senior
co-managers, and KeyBanc Capital Markets Inc., Loop Capital Markets LLC and
Mizuho Securities USA Inc. are acting as co-managers. Copies of the prospectus
supplement and accompanying prospectus may be obtained by visiting the SEC’s
website at www.sec.gov or by contacting Barclays Capital Inc., c/o Broadridge
Integrated Prospectus Distribution, 1555 Long Island Avenue, Edgewood, New York
11717, Telephone: 888-603-5847, E-mail: barclaysprospectus@broadridge.com;
Citigroup Global Markets Inc., Attention: Prospectus Department, Brooklyn Army
Terminal, 140 58th Street, 8th Floor, Brooklyn, New York 11220, Telephone:
877-858-5407; or J.P. Morgan Securities LLC, 383 Madison Avenue, New York, New
York 10179, Attention: High Grade Syndicate Desk – 3rd Floor, Telephone:
212-834-4533.

About NiSource

NiSource Inc. (NYSE: NI), based in Merrillville, Ind., is a Fortune 500 company
engaged in natural gas transmission, storage and distribution, as well as
electric generation, transmission and distribution. NiSource operating companies
deliver energy to 3.7 million customers located within the high-demand energy
corridor stretching from the Gulf Coast through the Midwest to New England.
Together, NiSource’s gas transmission and storage companies operate a
15,000-mile network of natural gas pipelines, 37 storage fields and serve some
of the nation’s largest and fastest-growing energy markets in the Northeast,
Midwest and Mid-Atlantic regions. Information about NiSource and its
subsidiaries is available via the Internet at www.nisource.com. NI-F

Forward-Looking Statements

This news release includes forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. Those statements include statements
regarding the intent, belief or current expectations of NiSource and its
management. Although NiSource believes that its expectations are based on
reasonable assumptions, it can give no assurance that its goals will be
achieved. Readers are cautioned that the forward-looking statements in this news
release are not guarantees of future performance and involve a number of risks
and uncertainties, and that actual results could differ materially from those
indicated by such forward-looking statements. Important factors that could cause
actual results to differ materially from those indicated by such forward-looking
statements include, but are not limited to, the following: weather; fluctuations
in supply and demand for energy commodities; growth opportunities for NiSource’s
businesses; increased competition in deregulated energy markets; the success of
regulatory and commercial initiatives; dealings with third parties over whom
NiSource has no control; actual operating experience of NiSource’s assets; the
regulatory process; regulatory and legislative changes; the impact of potential
new environmental laws or regulations; the results of material litigation;
changes in pension funding requirements; changes in general economic, capital
and commodity market conditions; and counterparty credit risk, and the matters
set forth in the “Risk Factors” section in NiSource’s 2010 Form 10-K and 2011
Forms 10-Q, many of which risks are beyond the control of NiSource. NiSource
expressly disclaims a duty to update any of the forward-looking statements
contained in this release.