UK Business Unit Update

Tullow Oil PLC
14 June 2005


News release


Tullow Oil plc - UK Business Unit Update


14 June 2005 - Tullow Oil plc (Tullow) today announces updates on three UK
Business Unit assets.

Tullow is a leading independent oil and gas, exploration and production group,
quoted on the London and Irish Stock Exchanges (symbol: TLW) and is a
constituent of the FTSE 250 Index. The Group has interests in over 90 production
and exploration licences in 16 countries and is currently focusing on three core
areas: NW Europe, West Africa and South Asia.

A full update on the rest of Tullow's activities will be provided in our Trading
Statement and Operational Update in July.


HIGHLIGHTS
     
•    First gas from the Tullow operated Horne & Wren development in the
     Southern North Sea

•    Successful Opal exploration well (formerly West Boulton)

•    Completion of the sale of the Alba and Caledonia assets to Itochu 
     Corporation


FIRST GAS FROM HORNE & WREN

Natural gas production from Horne & Wren, Tullow's first operated development in
the UK, commenced on 9 June 2005 and reached a stabilised flow rate of 60
mmscfd.  The flow rate will be ramped up to the plateau rate of 90 mmscfd over
the coming days.

The development, a 50:50 joint venture between Tullow and Centrica, comprises
two horizontal wells, a normally unmanned installation and a pipeline to the
Thames platform in which Tullow has a 67% interest.  The gas is processed at
Thames and compressed for export to the Tullow-operated Bacton Terminal.

Tullow first acquired minority interests in the Horne & Wren discoveries from BP
in 2001 and subsequently entered into a series of transactions that resulted in
Tullow operating the development with a 50% interest.  The fast-track
development was initiated following project sanction in June 2004 and the Field
Development Plan was approved by the DTI in October 2004.

Production from the Horne & Wren wells brings the throughput of the Thames
infrastructure to over 190 mmscfd, a four fold increase since early 2004. This
increase further reduces the unit operating cost of this regional hub and
extends the life of the Thames facility, thereby enhancing the value of Tullow's
other interests in the Thames Area fields.


OPAL GAS DISCOVERY (FORMERLY WEST BOULTON)

The Opal exploration well (43/25a-2W), operated by Gaz de France Britain, has
successfully encountered gas bearing reservoir sands in the targeted
Carboniferous section.  Tullow currently has a 46% interest in the discovery
although this may revert to the original equity of 30% if certain back-in rights
are exercised.

The discovery, located within Tullow's Caister Murdoch System ('CMS') core area
was suspended on 9 June 2005.  Information obtained from the well will now be
integrated with existing data to determine the extent of the accumulation and to
complete pre-development studies. In the event of a positive outcome to these
studies, the co-venturers plan to re-use the suspended well. The tie back
options include the nearby CMS infrastructure, in which Tullow and Gaz de France
Britain have a non operated interest.


COMPLETION OF THE SALE OF THE ALBA AND CALEDONIA ASSETS TO ITOCHU

On 8 June 2005 Tullow completed the sale of two subsidiaries holding minority
interests in the Alba and Caledonia oil fields in the Central North Sea to
Itochu Corporation for a headline consideration of $112 million. This
transaction was first announced on 12 April 2005.

Commenting today, Aidan Heavey, Chief Executive of Tullow said:

'The achievement of first gas from Horne & Wren and the Opal discovery are
further evidence of the excellent progress we are making in our Southern North
Sea gas business. In conjunction with a very strong UK gas market, these events
will create significant value for Tullow and enhance our position within the CMS
and Thames/Hewett core areas.  We look forward to further success in this
region.'


For further information contact:

Tullow Oil plc              Citigate Dewe Rogerson         Murray Consultants
([phone])          ([phone])             ([phone])
Aidan Heavey                Martin Jackson                 Joe Murray
Chris Perry                 George Cazenove


Notes to Editors

Tullow's UK interests are primarily focused on gas in the Southern North Sea
(SNS).  The Group entered the SNS with the acquisition of a portfolio of assets
from BP in 2001.  Since then, Tullow has substantially extended and enhanced its
position through exploration drilling, active development, participation in
licensing rounds and a series of bolt-on acquisitions.  Group interests include
the CMS and the Thames/Hewett areas, where it is the operator of the Hewett
fields and of the Bacton Gas Terminal.  A further significant step was taken
with the completion of the acquisition of the Schooner and Ketch operated assets
on 31 March 2005.

In Africa, Tullow has production in Gabon, Cote d'Ivoire, Congo (Brazzaville)
and Equatorial Guinea. Tullow also has exploration programmes in Morocco,
Mauritania, Senegal, Cameroon, and Uganda.

In South Asia, Tullow has production and exploration interests in Pakistan and
exploration activities in India and Bangladesh.

For further information please refer to our website at www.tullowoil.com



                                      ENDS




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