ACS Increases Offer for HOCHTIEF Shares by 12.5 Percent

This announcement and the information contained herein are restricted and are not for release, publication or distribution, in whole or in part, in or into the United States or Japan.

MADRID, December 15, 2010 - Grupo ACS (ACS, Actividades de Construcción y Servicios, S.A.)
today announced that it increases its exchange offer for all outstanding
HOCHTIEF shares. With this improvement, HOCHTIEF shareholders will now
receive nine instead of eight ACS shares for every five HOCHTIEF shares,
which represents a 12.5 percent improvement over the initial offer. The new
exchange ratio will also apply to shareholders who have already tendered
their shares. All other terms and conditions of the offer remain unchanged.
As announced on December 1, the acceptance period of the offer will end at 12
midnight CET on December 29, 2010.

On the basis of yesterday's closing price of ACS (14 December
2010), the increased offer represents a price for each HOCHTIEF share of EUR
64.49. This new price represents a premium of 26.5 percent over the
three-month weighted average price of the HOCHTIEF share at 16 September
2010, the time of the announcement of the offer of ACS to HOCHITIEF
shareholders.

ACS is confident to succeed with the increased offer.

More information about the public tender offer is available at
www.acs-offer.com.

About Grupo ACS

Grupo ACS (ACS, Actividades de Construcción y Servicios, S.A.),
headquartered in Madrid/Spain, is a world leader in infrastructure
development. In 2009, the Group's revenues totaled EUR15,606 million. ACS has
more than 146,000 employees operating in 41 countries. ACS is listed on the
Madrid Stock Exchange.

Important Notice:

This announcement is neither an offer to purchase nor a solicitation of
an offer to sell shares in HOCHTIEF Aktiengesellschaft (the "HOCHTIEF
Shares"). Moreover, the announcement is neither an offer to purchase nor a
solicitation to purchase shares in ACS, Actividades de Construcción y
Servicios, S.A. (the "ACS Shares"). The public offer by ACS, Actividades de
Construcción y Servicios, S.A. to the shareholders of HOCHTIEF
Aktiengesellschaft is exclusively made on the basis of the terms set out in
the offer document. Investors and holders of HOCHTIEF Shares are strongly
recommended to read the offer document and all announcements published in
connection with the public offer, since they contain important information.

Subject to certain exceptions, the public offer will not be made directly
or indirectly, in or into the United States, Japan or any other jurisdiction
where to do so would constitute a violation of the laws of such jurisdiction,
or by use of the mails or by any means or instrumentality (including without
limitation, facsimile transmission, telephone and the internet) of interstate
or foreign commerce, or any facility of a national securities exchange, of
the United States, Japan, or any other jurisdiction where to do so would
constitute a violation of the laws of such jurisdiction. Accordingly, copies
of this announcement or any accompanying documents are not being, directly or
indirectly, mailed or otherwise distributed, forwarded or transmitted in,
into or from the United States, Japan, or any other jurisdiction where to do
so would constitute a violation of the laws of such jurisdiction.

The ACS Shares have not been, and will not be, registered under the US
Securities Act of 1933 or with any securities regulatory authority of any
state or other jurisdiction of the United States or under the applicable
securities laws of Japan. Accordingly, subject to certain exceptions, the ACS
Shares may not be offered or sold within the United States or Japan or any
other jurisdiction where to do so would constitute a violation of the laws of
such jurisdiction, or to or for the account or benefit of any person in the
United States or Japan.

To the extent permissible under applicable law or regulation, ACS and
persons acting on its behalf may from time to time make certain purchases of,
or arrangements to purchase, directly or indirectly, HOCHTIEF Shares or any
securities that are immediately convertible into, exchangeable for, or
exercisable for, HOCHTIEF Shares, other than pursuant to the public offer,
before, during or after the period in which the offer remains open for
acceptance. These purchases may occur either in the open market at prevailing
prices or in private transactions at negotiated prices. Any information about
such purchases and arrangements to purchase will be disclosed as required by
law or regulation in Germany or other relevant jurisdictions.

This announcement includes forward-looking statements about ACS, HOCHTIEF
and the enlarged group. By their nature, forward-looking statements involve
risks and uncertainties because they relate to events and depend on
circumstances that may or may not occur in the future. ACS cautions you that
forward-looking statements are not guarantees of the occurrence of such
future events or of future performance and that in particular the actual
results of operations, financial condition and liquidity, and the development
of the industry in which ACS and HOCHTIEF operate may differ materially from
those made in or suggested by the forward-looking statements contained in
this announcement. Any forward-looking statements speak only as at the date
of this announcement. Except as required by applicable law, ACS does not
undertake any obligation to update or revise publicly any forward-looking
statement, whether as a result of new information, future events or
otherwise.

    Company Contacts:

    German and international media:

    Phoebe Kebbel
    Hering Schuppener Consulting
    Phone: +49-69-921874-77
    Mobile: +49-173-2862110
    pkebbel@heringschuppener.com

    Oda Wöltje
    Hering Schuppener Consulting
    Phone: +49-69-921874-47
    Mobile: +49-(151)-15176631
    owoeltje@heringschuppener.com

    Australian media:

    Kate Inverarity
    Nightingale Communications
    Phone: +61-3-9614-6930
    Mobile: +61-413-163-020
    kate@nightingalecommunications.com.au

    Lisa Keenan
    Nightingale Communications
    Phone: +61-3-9614 6930
    Mobile: +61-409-150 771
    lisa@nightingalecommunications.com.au

    Investor Relations:

    Grupo ACS
    Avda. Pío XII, n degrees 102
    28036 Madrid, Spain
    Tel: +34-91-343-92-00
    Fax: +34-91-343-94-56
    e-mail: infogrupoacs@grupoacs.com

Company Contacts: German and international media: Phoebe Kebbel, Hering Schuppener Consulting, Phone: +49-69-921874-77, Mobile: +49-173-2862110, pkebbel at heringschuppener.com; Oda Wöltje, Hering Schuppener Consulting, Phone: +49-69-921874-47, Mobile: +49 (151) 15176631, owoeltje at heringschuppener.com; Australian media: Kate Inverarity, Nightingale Communications, Phone: +61-3-9614-6930, Mobile: +61-413-163-020, kate at nightingalecommunications.com.au; Lisa Keenan, Nightingale Communications, Phone: +61-3-9614 6930, Mobile: +61-409-150-771, lisa at nightingalecommunications.com.au; Investor Relations: Grupo ACS Avda. Pío XII, n degrees 102, 28036 Madrid, Spain, Tel: +34-91-343-92-00, Fax: +34-91-343-94-56, e-mail: infogrupoacs at grupoacs.com