Access Midstream Partners to Acquire Midstream Gathering and Processing Assets from Chesapeake Energy Corporation for $2.16

  Access Midstream Partners to Acquire Midstream Gathering and Processing
  Assets from Chesapeake Energy Corporation for $2.16 Billion and Announces
  Planned Strategic Investment by Global Infrastructure Partners and Williams

  Acquisition adds natural gas gathering and processing assets in the Eagle
   Ford, Utica and Niobrara shale plays and expands Access’ position in the
                    Haynesville and Marcellus shale plays

Williams to concurrently acquire 50% GP interest and 23% LP interest in Access
            Midstream Partners from Global Infrastructure Partners

Global Infrastructure Partners and Williams commit to contribute $1.16 billion
                     additional equity funding to Access

Business Wire

OKLAHOMA CITY -- December 11, 2012

Access Midstream Partners, L.P. (NYSE:ACMP) today announced it has agreed to
acquire Chesapeake Midstream Operating, L.L.C., a wholly owned subsidiary of
Chesapeake Midstream Development, L.L.C., from Chesapeake Energy Corporation
(NYSE:CHK) for $2.16 billion in cash. The acquisition adds natural gas
gathering and processing assets in the Eagle Ford, Utica and Niobrara
liquids-rich plays and expands Access’ existing position in both the
Haynesville and Marcellus dry gas plays. Separately, Access and Chesapeake
have agreed to extend Access’ exclusivity period with respect to Chesapeake’s
remaining assets in the Mid-Continent region until March 1, 2013.

The acquisition of the midstream assets is a transformational opportunity for
Access and will create the leading gathering and processing MLP in the
country. Upon completion of this transaction, Access will have large scale,
well established footprints in virtually all of the major unconventional
basins in the United States. The acquisition provides immediate entry to
gathering opportunities in key liquids-rich regions and to the processing and
fractionation segments of the midstream value chain. Consistent with the
Partnership’s current portfolio of assets, the acquired assets are anchored by
long-term, market-based, cost of service agreements with Chesapeake and other
producer customers. This long-term, cost of service contract structure
provides protections for capital, inflation and re-contracting risks resulting
in highly visible and predictable cash flows. The acquisition is expected to
close by the end of 2012 and be immediately accretive to distributable cash
flow.

Concurrent with the closing of the acquisition, Williams (NYSE:WMB) will
acquire 50 percent of the general partner of Access and 34.5 million of
Access’ subordinated limited partner units from Global Infrastructure
Partners. Williams’ vast midstream experience will complement GIP’s strong
strategic and financial sponsorship as Access continues to execute on its best
in class business model.

GIP and Williams have entered into a subscription agreement to purchase an
aggregate of up to $1.16 billion of additional limited partner interests,
including $350 million of paid in kind equity, demonstrating their substantial
commitment to Access’ long-term success. Access has concurrently obtained debt
commitments to finance the balance of the purchase price. Citigroup, Barclays
and UBS Investment Bank have provided commitments for a $1.0 billion
acquisition bridge facility. Barclays and Citi acted as exclusive financial
advisors to Access with respect to the acquisition and its related financings.

Terms of the CMO acquisition were unanimously approved by the Board of
Directors of Access’ general partner and by the Board’s Conflicts Committee,
which is comprised entirely of independent directors. The Conflicts Committee
engaged Tudor, Pickering, Holt & Co. Securities, Inc. to act as its financial
advisor and Richards, Layton & Finger, P.A. to act as its legal advisor and
also received advice from Jones Day which acted as counsel to Access.

                             Management Comments

J. Mike Stice, Access Midstream Partners’ Chief Executive Officer, commented,
“The acquisition of these midstream assets is a transformational opportunity
for Access. Following this transaction, Access will become the largest
gathering and processing MLP as measured by invested capital and throughput
volume and will have a substantially diversified portfolio with a critical
midstream position in the most prominent liquids-rich basins in the United
States. The extension of our services into gas processing, fractionation and
NGL pipelines will enhance our ability to grow and deliver additional value to
our unitholders going forward.

“I know the Williams team well and am very excited to add their world-class
sponsorship to Access. Our ability to leverage Williams’ deep midstream
operational and development capabilities will significantly benefit our
expanded operations and lead to new growth opportunities for years to come.
With GIP’s continued position, we now have two great sponsors with a
substantial commitment to Access and a strong belief in our assets and
business model.”

                         Conference Call Information

A conference call to discuss the acquisition has been scheduled for Tuesday,
December 11, 2012 at 5:45 p.m. EST. The telephone number to access the
conference call is 785-424-1741 or toll-free 877-688-0767. The passcode for
the call is 303421. We encourage those who would like to participate in the
call to dial the access number between 5:35 and 5:45 p.m. EST. For those
unable to participate in the conference call, a replay will be available for
audio playback from 8:00 a.m. EST on December 12, 2012 through 8:00 a.m. EST
on December 26, 2012. The number to access the conference call replay is
719-884-8882 or toll-free 888-348-4629. The passcode for the replay is 303421.
The conference call will also be webcast live on the Internet and can be
accessed by going to the Partnership’s website at www.accessmidstream.com in
the "Events" subsection of the "Investors" section of the website. An archive
of the conference call webcast will also be available on the website.

Access Midstream Partners, L.P. (NYSE:ACMP) is the industry’s largest
gathering and processing master limited partnership as measured by throughput
volume and owns, operates, develops and acquires natural gas gathering systems
and other midstream energy assets. Headquartered in Oklahoma City, the
Partnership's operations are focused on the Barnett Shale, Haynesville Shale,
Marcellus Shale and Mid-Continent regions of the U.S. The Partnership’s common
units are listed on the New York Stock Exchange under the symbol ACMP. Further
information is available at www.accessmidstream.com where the Partnership
routinely posts announcements, updates, events, investor information and
presentations and all recent press releases.

This press release includes forward-looking statements. Forward-looking
statements give our current expectations or forecasts of future events. They
include but are not limited to our business strategy and plans and objectives
for future acquisitions, including the proposed acquisition of Chesapeake
Midstream Operating, L.L.C and the proposed financing of that acquisition. We
caution you not to place undue reliance on our forward-looking statements,
which speak only as of the date of this release, and we undertake no
obligations to update this information. Although we believe the expectations
and forecasts reflected in these and other forward-looking statements are
reasonable, we can give no assurance they will prove to be correct. They can
be affected by inaccurate assumptions or by known or unknown risks and
uncertainties. Factors that could cause actual results to differ materially
from expected results are described under “Risk Factors” in our 2011 Annual
Report on Form 10-K and our other SEC filings.

Contact:

Access Midstream Partners
Investor Contact:
Dave Shiels, CFO, 405-935-6224
dave.shiels@accessmidstream.com
or
Media Contacts:
Debbie Nauser, 405-935-1739
debbie.nauser@accessmidstream.com
or
Tom Johnson, 212-371-5999
tbj@abmac.com