Williams Partners’ Northwest Pipeline Commences Registered Exchange Offer for its 4.000% Senior Notes Due 2027

TULSA, Okla.–(BUSINESS WIRE)–Northwest Pipeline LLC (“Northwest Pipeline”), a wholly owned subsidiary
of Williams Partners L.P. (NYSE: WPZ), announced today that it has
commenced an offer to exchange any and all of its $250 million in
aggregate principal amount of outstanding 4.000% Senior Notes due 2027
(the “Original Notes”) for an equal amount of its registered 4.000%
Senior Notes due 2027 (the “Exchange Notes”).

The terms of the Exchange Notes are identical in all material respects
to those of the Original Notes, except that the Exchange Notes have been
registered under the Securities Act of 1933, as amended, and the
transfer restrictions, registration rights and additional interest
provisions relating to the Original Notes do not apply to the Exchange
Notes. The purpose of the Exchange Offer is to fulfill Northwest
Pipeline’s obligations under the registration rights agreement entered
into in connection with the issuance of the Original Notes. Northwest
Pipeline will not receive any proceeds from the exchange offer.

The exchange offer will expire at 5:00 p.m., New York City time,
on February 28, 2018, unless extended (such date and time, as may be
extended, the “Expiration Date”). The settlement date for the exchange
offer will occur promptly following the Expiration Date. The terms of
the exchange offer and other information relating to Northwest Pipeline
and the Exchange Notes are set forth in a prospectus dated January 30,
2018, a copy of which has been filed with the Securities and Exchange
Commission. Northwest Pipeline has not authorized any person to provide
information other than as set forth in the prospectus.

Copies of the prospectus and the transmittal letter governing the
exchange offer can be obtained from the exchange agent, The Bank of New
York Mellon Trust Company, N.A., by faxing a request to (732) 667-9408
or by writing via regular or certified mail, or overnight courier, to
The Bank of New York Mellon Trust Company, N.A., Corporate Trust
Operations—Reorganization Unit, 111 Sanders Creek Parkway, East
Syracuse, New York, 13057.

This press release is for informational purposes only and does not
constitute an offer to sell nor a solicitation of an offer to buy any
security. The exchange offer is being made solely pursuant to the
prospectus dated January 30, 2018, including any supplements thereto,
and only to such persons and in such jurisdictions as is permitted under
applicable law.

About Williams Partners

Williams Partners is an industry-leading, large-cap natural gas
infrastructure master limited partnership with a strong growth outlook
and major positions in key U.S. supply basins. Williams Partners has
operations across the natural gas value chain including gathering,
processing and interstate transportation of natural gas and natural gas
liquids. Williams Partners owns and operates more than 33,000 miles of
pipelines system wide – including the nation’s largest volume and
fastest growing pipeline – providing natural gas for clean-power
generation, heating and industrial use. Williams Partners’ operations
touch approximately 30 percent of U.S. natural gas. Tulsa, Okla.-based
Williams (NYSE: WMB), a premier provider of large-scale U.S. natural gas
infrastructure, owns approximately 74 percent of Williams Partners.

Portions of this document may constitute “forward-looking statements” as
defined by federal law. Although the partnership believes any such
statements are based on reasonable assumptions, there is no assurance
that actual outcomes will not be materially different. Additional
information about issues that could lead to material changes in
performance is contained in the partnership’s annual and quarterly
reports filed with the Securities and Exchange Commission.

Contacts

Williams Partners L.P.
Media Contact:
Keith Isbell,
918-573-7308
or
Investor Contact:
Brett Krieg,
918-573-4614