UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

_________________

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of
the Securities Exchange Act of 1934

_________________

Date of Report  
(Date of earliest
event reported): May 17, 2007

TierOne Corporation
(Exact name of registrant as specified in its charter)

Wisconsin
000-50015
04-3638672
(State or other (Commission File (IRS Employer
jurisdiction of Number) Identification No.)
incorporation)

1235 “N” Street, Lincoln, Nebraska 68508
(Address of principal executive offices, including zip code)

(402) 475-0521

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

_________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[x] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[_] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[_] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[_] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)


Item 8.01. Other Events.

        On May 17, 2007, TierOne Corporation, a Wisconsin corporation (“TierOne”), and CapitalSource Inc., a Delaware Corporation, (“CapitalSource”), issued a press release (the “Press Release”) announcing that they had entered into an Agreement and Plan of Merger (the “Merger Agreement”), dated May 17, 2007. Pursuant to the Merger Agreement, TierOne will merge into CapitalSource TRS Inc., a wholly-owned subsidiary of CapitalSource.

        A copy of the Press Release of TierOne and CapitalSource announcing the execution of the Merger Agreement is included herein as Exhibit 99.1 and is incorporated herein by reference.

Forward Looking Statements

        This release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including certain plans, expectations, goals, and projections, and including statements about the benefits of the merger between CapitalSource and TierOne, which are subject to numerous assumptions, risks, and uncertainties. Actual results could differ materially from those contained or implied by such statements for a variety of factors including: the businesses of CapitalSource and TierOne may not be integrated successfully or such integration may take longer to accomplish than expected; disruption from the merger may make it more difficult to maintain relationships with clients, associates, or suppliers; the required governmental approvals of the merger may not be obtained or if obtained may not be on the proposed terms and schedule; TierOne’s stockholders may not approve the merger; changes in economic conditions; movements in interest rates; competitive pressures on product pricing and services; success and timing of other business strategies; the nature, extent, and timing of governmental actions and reforms; and extended disruption of vital infrastructure; and other factors described in CapitalSource’s 2006 Annual Report on Form 10-K, TierOne’s 2006 Annual Report on Form 10-K, and documents subsequently filed by CapitalSource and TierOne with the Securities and Exchange Commission. All forward-looking statements included in this news release are based on information available at the time of the release. CapitalSource and TierOne are under no obligation to (and expressly disclaim any such obligation to) update or alter their forward-looking statements, whether as a result of new information, future events or otherwise.

Additional Information About the Transaction

        CapitalSource intends to file with the SEC a registration statement that will include the proxy statement/prospectus of TierOne and other relevant documents to be mailed to security holders in connection with the proposed transaction. WE URGE INVESTORS TO READ THE PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT CAPITALSOURCE, TIERONE AND THE PROPOSED TRANSACTION. A definitive proxy statement will be sent to security holders of TierOne seeking approval of the proposed transaction. Investors will be able to obtain these materials (when they are available) and other documents filed with the SEC free of charge at the SEC’s website, www.sec.gov. In addition, a copy of the proxy statement/prospectus (when it becomes available) may be obtained free of charge by directing a request to CapitalSource Inc., 4445 Willard Avenue, 12th Floor, Chevy Chase, Maryland 20815, Attention: Tony Skarupa, Vice President, Finance, CapitalSource; or by directing a request to TierOne Corporation, 1235 N Street, Lincoln, Nebraska 68508, Attention: Edward J. Swotek, Senior Vice President, Investor Relations Department.

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        This document is not a solicitation of a proxy from any security holder of TierOne or an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

        TierOne, its directors and executive officers and certain other persons may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding TierOne’s directors and executive officers is available in the proxy statement filed with the SEC by TierOne on March 30, 2007. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the proxy statement/prospectus and other relevant materials to be filed with the SEC when they become available.

Item 9.01. Financial Statements and Exhibits.

  (a) Not applicable.

  (b) Not applicable.

  (c) Not applicable.

  (d) Exhibits. The following exhibit is being filed herewith:

  (99.1) Joint Press Release of TierOne Corporation and CapitalSource Inc., dated May 17, 2007.

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SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

TIERONE CORPORATION


Date: May 17, 2007
By:  /s/ Gilbert G. Lundstrom
        Gilbert G. Lundstrom
        Chairman of the Board and Chief Executive Officer









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TIERONE CORPORATION

Exhibit Index to Current Report on Form 8-K
Dated May 17, 2007

Exhibit
Number

(99.1) Joint Press Release of TierOne Corporation and CapitalSource Inc., dated May 17, 2007.













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