UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

(Amendment No.     )

Filed by the Registrant x Filed by a Party other than the Registrant ¨

Check the appropriate box:

¨  Preliminary Proxy Statement

¨  Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

¨  Definitive Proxy Statement

¨  Definitive Additional Materials

x  Soliciting Material Pursuant to § 240.14a-11(c) or § 240.14a-12

BUCYRUS INTERNATIONAL, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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x  No fee required.

¨  Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.

(1) Title of each class of securities to which transaction applies:

(2) Aggregate number of securities to which transaction applies:

(3) Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (Set forth the amount on which the filing fee is calculated and state how it was determined):

(4) Proposed maximum aggregate value of transaction:

(5) Total fee paid:

¨ Fee paid previously with preliminary materials.

¨ Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

(1) Amount Previously Paid:

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(4) Date Filed:

BUCYRUS 1100 Milwaukee Avenue Ÿ P.O. Box 500 South Milwaukee, Wisconsin 53172-0500, USA +1 414 768-4000

24. November 2010

Sehr geehrter Kunde,

wie Sie vielleicht schon gehört haben, haben wir am Montag, den 15. November unsere Vereinbarung zur Übernahme von Bucyrus durch Caterpillar, dem weltweit führenden Hersteller von Bau- und Bergbaumaschinen, Diesel- und Erdgasmotoren sowie Industriegasturbinen, bekannt gegeben. Im Anhang finden Sie die entsprechende Pressemitteilung. Ich möchte jedoch die Gelegenheit nutzen und Sie persönlich über die Neuigkeiten informieren und auch darüber, was diese für unsere Kunden bedeuten.

Ich bin überzeugt, dass diese Transaktion für Bucyrus und unsere Interessensvertreter eine ausgezeichnete Chance bietet. Wie Sie wissen, ist das Produktangebot von Bucyrus derzeit das umfassendste im Bereich der Maschinen für den über- und untertägigen Bergbau. Zudem ist Bucyrus Technologieführer und eine Premiummarke. Diese Stärken hat Caterpillar erkannt und beabsichtigt, auf Bucyrus als eine Basis für Wachstum in der globalen Bergbaumaschinenindustrie aufzubauen. Im Rahmen dieses Vorhabens soll die Marke Bucyrus mit den traditionsreichsten Bucyrus-Produkten bestehen bleiben.

Vielen unserer Kunden ist Caterpillar ein Begriff und es steht zweifellos außer Frage, dass es sich bei Caterpillar um ein erstklassiges globales Unternehmen handelt. Am wichtigsten ist vielleicht jedoch die Tatsache, dass sich Caterpillar, ebenso wie Bucyrus, innovativen Produkten und einem herausragenden Kundenservice verschrieben hat. Mit der Übernahme werden wir Teil eines großen, dynamischen Unternehmens. Dies bedeutet, dass unsere Kunden sowohl vom Zugang zu beträchtlichen weltweiten Ressourcen profitieren können, als auch durch unser kontinuierliches Streben nach technologischen Innovationen.

Wir freuen uns über diese Neuigkeiten. Allerdings ist die Bekanntgabe nur der erste Schritt im gesamten Prozess. Rund um den Globus gilt es nun, rechtliche Genehmigungen einzuholen. Deshalb wird sich die Übernahme über mehrere Monate erstrecken. Bis zum letztendlichen Vertragsabschluss werden die Unternehmen unabhängig weiterbetrieben und für unser Geschäft ändert sich vorerst nichts. Die Bedürfnisse unserer Kunden bleiben für Bucyrus oberste Priorität. Wir versichern Ihnen gewohnte branchenführende Produkte und hohe Servicequalität.

Über die weiteren Geschehnisse werden wir Sie auf dem Laufenden halten. Falls Sie in der Zwischenzeit Fragen haben, können Sie sich jederzeit an Ihren Ansprechpartner wenden.

Wir schätzen Sie als Kunden und freuen uns, Ihnen auch in Zukunft unsere Dienstleistungen anzubieten. Vielen Dank für Ihre Unterstützung.

Mit freundlichen Grüßen,

Timothy W. Sullivan

President und CEO

BUCYRUS 1100 Milwaukee Avenue Ÿ P.O. Box 500 South Milwaukee, Wisconsin 53172-0500, USA +1 414 768-4000

Additional Information Relating to Bucyrus and Where to Find It

This communication may be deemed to be solicitation material in respect of the proposed acquisition of Bucyrus by Caterpillar. In connection with the proposed merger, Bucyrus intends to file relevant materials with the Securities and Exchange Commission (the “SEC”), including a proxy statement on Schedule 14A, which will be mailed to stockholders of Bucyrus.

Bucyrus stockholders are urged to read all relevant documents filed with the SEC, including the proxy statement, because they will contain important information about the proposed transaction.

Investors and security holders will be able to obtain free copies of the proxy statement (when available), as well as other filed documents, without charge, at the SEC’s website (http://www.sec.gov). Free copies of Bucyrus’s filings may be obtained by directing a request to Bucyrus’s Investor Relations by telephone to (414)768-4000, in writing to Bucyrus, Attention: Investor Relations, 1100 Milwaukee Avenue, South Milwaukee, WI 53172, by email to amalingowski@bucyrus.com or at Bucyrus’s website (http://www.bucyrus.com).

Bucyrus and its directors and executive officers may be deemed, under SEC rules, to be participants in the solicitation of proxies from the stockholders of Bucyrus with respect to the proposed transaction. More detailed information regarding the identity of the potential participants, and their direct or indirect interests, by securities holdings or otherwise, will be set forth in the proxy statement and other materials to be filed with the SEC in connection with the proposed transaction. Information regarding Bucyrus’s directors and executive officers is also available in Bucyrus’s definitive proxy statement for its 2010 Annual Meeting of Stockholders filed with the SEC on March 12, 2010. These documents are available free of charge at the SEC’s web site at http://www.sec.gov and from Investor Relations at Bucyrus.

Caution Concerning Forward-Looking Statements Relating to Bucyrus

Statements in this communication that relate to Bucyrus’s future plans, objectives, expectations, performance, events and the like may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Future events, risks and uncertainties, individually or in the aggregate, could cause our actual results to differ materially from those expressed or implied in these forward-looking statements. These forward-looking statements may be identified by the use of predictive, future tense or forward-looking terminology, such as “believes,” “anticipates,” “expects,” “estimates,” “intends,” “may,” “will” or similar terms. The material factors and assumptions that could cause actual results to differ materially from current expectations include, without limitation, the following: (1) the inability to close the merger in a timely manner; (2) the inability to complete the merger due to the failure to obtain stockholder approval and adoption of the merger agreement and approval of the merger or the failure to satisfy other conditions to completion of the merger, including required regulatory approvals; (3) the failure of the transaction to close for any other reason; (4) the effect of the announcement of the transaction on Bucyrus’s business relationships, operating results and business generally; (5) the possibility that the anticipated synergies and cost savings of the merger will not be realized, or will not be realized within the expected time period; (6) the possibility that the merger may be more expensive to complete than anticipated, including as a result of unexpected factors or events; (7) diversion of management’s attention from ongoing business concerns; (8) general competitive, economic, political and market conditions and fluctuations; (9) actions taken or conditions imposed by the governmental or regulatory authorities; (10) adverse outcomes of pending or threatened litigation or government investigations; (11) the impact of competition in the industries and in the specific markets in which Bucyrus operates; and (12) other factors that may affect future results of the combined company described in the section entitled “Risk Factors” in the proxy statement to be mailed to Bucyrus’s stockholders Bucyrus’s filings with the SEC that are available on the SEC’s web site located at http://www.sec.gov, including the section entitled “Risk Factors” in Bucyrus’s Annual Report on Form 10-K for the fiscal year ended December 31, 2009. Readers are strongly urged to read the full cautionary statements contained in those materials. All forward-looking statements attributable to Bucyrus are expressly qualified in their entirety by the foregoing cautionary statements. We assume no obligation to update any forward-looking statements to reflect events that occur or circumstances that exist after the date on which they were made.