SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

[Rule 13d-101]

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a)

AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a)

(Amendment No. 7)*

Clearwire Corporation

(Name of Issuer)

Class A Common Stock

(Title of Class of Securities)

18538Q105

(CUSIP Number)

David K. Schumacher

General Counsel

Crest Financial Limited

JP Morgan Chase Tower

600 Travis, Suite 6800

Houston, TX 77002

Tel: (713) 222 6900

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

Copies to:

Stephen M. Gill

Kai Haakon E. Liekefett

Vinson & Elkins LLP

First City Tower

1001 Fannin Street, Suite 2500

Houston, TX 77002

Tel: (713) 758 2222

April 10, 2013

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note. Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (the “Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on following pages)

This Amendment No. 7 (this “Amendment”) amends and supplements the Statement on Schedule 13D (the “Schedule 13D”) of Crest Financial Limited (“CFL”), Crest Investment Company (“CIC”), the Jamal and Rania Daniel Revocable Trust (the “Jamal and Rania Daniel Trust”), Mr. Jamal Daniel, Mrs. Rania Daniel, DTN LNG, LLC (“DTN LNG”), DTN Investments, LLC (“DTN Investments”), the Daria Daniel 2003 Trust (the “Daria Daniel Trust”), the Thalia Daniel 2003 Trust (the “Thalia Daniel Trust”), the Naia Daniel 2003 Trust (the “Naia Daniel Trust”), Mr. John M. Howland, Mr. Eric E. Stoerr, the Halim Daniel 2012 Trust (the “Halim Daniel Trust”), Mr. Michael Wheaton, solely in his capacity as trustee of the Halim Daniel Trust, Mr. Halim Daniel, Uniteg Holding SA (“Uniteg”) and Crest Switzerland, LLC (“Crest Switzerland” and, together with CFL, CIC, the Jamal and Rania Daniel Trust, Mr. Jamal Daniel, Mrs. Daniel, DTN LNG, DTN Investments, the Daria Daniel Trust, the Thalia Daniel Trust, the Naia Daniel Trust, Mr. Howland, Mr. Stoerr, the Halim Daniel Trust, Mr. Wheaton, solely in his capacity as trustee of the Halim Daniel Trust, Mr. Halim Daniel, Uniteg and Crest Switzerland, the “Reporting Persons”) that was filed in respect of Clearwire Corporation (the “Issuer”) on June 1, 2012 and amended by Amendment No. 1 filed on November 7, 2012 (“Amendment No. 1”), Amendment No. 2 filed on December 18, 2012 (“Amendment No. 2”), Amendment No. 3 filed on March 13, 2013 (“Amendment No. 3”), Amendment No. 4 filed on March 20, 2013 (“Amendment No. 4”), Amendment No. 5 filed on April 4, 2013 (“Amendment No. 5”) and Amendment No. 6 filed on April 9, 2013 (“Amendment No. 6”).

Items 2(c) and (f) of the Schedule 13D are hereby amended and restated in their entirety as follows:

CFL is a limited partnership under the laws of the State of Texas. Its principal business is investing in securities. The general partner of CFL is CIC, which owns a 1% interest in CFL. The sole limited partner of CFL is the Jamal and Rania Daniel Trust, which owns the remaining 99% interest in CFL.

CIC is a corporation under the laws of the State of Texas. Its principal business is investing in securities and serving as the general partner of CFL. The sole shareholder of CIC is the Jamal and Rania Daniel Trust, which owns a 100% interest in CIC.

The Jamal and Rania Daniel Trust is a revocable trust under the laws of the State of Texas. Its trustee is Mr. Daniel. Its grantors are Mr. Jamal Daniel and Mrs. Rania Daniel, who have joint power to revoke the trust.

Mr. Jamal Daniel is a citizen of the United States of America. His principal occupation is serving as President of CFL, as the Sole Director and President of CIC and as the trustee under the Jamal and Rania Daniel Trust.

Mrs. Rania Daniel is a citizen of the United States of America. Her principal occupation is homemaker.

DTN LNG is a limited liability company under the laws of the State of Delaware. Its principal business is investing in securities. The sole member of DTN LNG is DTN Investments, which owns a 100% interest in DTN LNG.

DTN Investments is a limited liability company under the laws of the State of Delaware. Its principal business is investing in securities. The members of DTN Investments are the Daria Daniel Trust, the Thalia Daniel Trust and the Naia Daniel Trust, each of which owns a 33 ¹/₃% interest in DTN Investments.

The Daria Daniel Trust is an irrevocable trust under the laws of the State of Texas. Its trustee is Mr. Howland.

The Thalia Daniel Trust is an irrevocable trust under the laws of the State of Texas. Its trustee is Mr. Howland.

The Naia Daniel Trust is an irrevocable trust under the laws of the State of Texas. Its trustee is Mr. Howland.

Mr. Howland is a citizen of the United States of America. His principal occupation is serving as the trustee under the Daria Daniel Trust, the Thalia Daniel Trust and the Naia Daniel Trust.

Mr. Stoerr is a citizen of the United States of America. His principal occupation is serving as Senior Vice President of Energy of CIC.

The Halim Daniel Trust is a revocable trust under the laws of the Cayman Islands. Its trustee is Mr. Wheaton. Its grantor is Mr. Halim Daniel, who has the power to revoke the trust.

Mr. Halim Daniel is a citizen of Lebanon. His principal occupation is serving as a business executive.

Mr. Michael Wheaton is a citizen of the Cayman Islands. His principal occupation is as director of Axis International Management, Ltd.

Uniteg is a Société Anonyme under the laws of Switzerland. Its principal business is serving as a holding company. Crest Switzerland owns 100% of the interests in Uniteg.

Crest Switzerland is a limited liability company under the laws of the State of Delaware. Its principal business is investing in securities. CFL and DTN Investments each own 50% of the interests in Crest Switzerland.

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following paragraph after the first paragraph thereof:

On April 10, 2013, CFL and CIC (collectively, the “Participants”) filed with the Securities and Exchange Commission (the “SEC”) a preliminary proxy statement and accompanying proxy card relating to Participants’ intention to solicit proxies from the stockholders of the Issuer in connection with a special meeting of such stockholders to be held to vote upon the proposed transaction between the Issuer and Sprint-Nextel Corporation (the “Preliminary Proxy Statement”) and issued a press release relating thereto (the “Press Release”), a copy of which is attached hereto as Exhibit 2 and is incorporated herein by reference.

Item 4 of the Schedule 13D is hereby amended and supplemented by replacing the tenth paragraph thereof (counting the above paragraph) with the following paragraph:

THE PRELIMINARY PROXY STATEMENT IS AVAILABLE AT NO CHARGE ON THE WEBSITE OF THE PARTICIPANTS’ PROXY SOLICITOR AT HTTP://WWW.DFKING.COM/CLWR AND ON THE SEC’S WEBSITE AT HTTP://WWW.SEC.GOV. THE PARTICIPANTS INTEND TO FILE WITH THE SEC A DEFINITIVE PROXY STATEMENT AND ACCOMPANYING PROXY CARD IN CONNECTION WITH SUCH PROXY SOLICITATION. WHEN COMPLETED, ANY SUCH DEFINITIVE PROXY STATEMENT AND PROXY CARD WILL BE FURNISHED TO SOME OR ALL OF THE STOCKHOLDERS OF THE ISSUER AND WILL, ALONG WITH OTHER RELEVANT DOCUMENTS, BE AVAILABLE AT NO CHARGE ON THE WEBSITE OF THE PARTICIPANTS’ PROXY SOLICITOR AT HTTP://WWW.DFKING.COM/CLWR AND ON THE SEC’S WEBSITE AT HTTP://WWW.SEC.GOV. IN ADDITION, THE PARTICIPANTS WILL PROVIDE COPIES OF THE DEFINITIVE PROXY STATEMENT AND ACCOMPANYING PROXY CARD (WHEN AVAILABLE) AT NO CHARGE UPON REQUEST. INFORMATION RELATING TO THE PARTICIPANTS IN SUCH PROXY SOLICITATION IS CONTAINED IN THE PRELIMINARY PROXY STATEMENT. STOCKHOLDERS OF THE ISSUER ARE ADVISED TO READ THE PRELIMINARY PROXY STATEMENT, WHICH IS AVAILABLE NOW, AND ANY DEFINITIVE PROXY STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION, INCLUDING ADDITIONAL INFORMATION RELATED TO THE PARTICIPANTS IN ANY SUCH SOLICITATION.

Item 6 of the Schedule 13D is hereby amended and restated in its entirety as follows:

Other than Asset Purchase Agreement as described in Item 3 hereof (which has been fully performed by the parties thereto in 2004), the Joint Filing Agreement attached hereto as Exhibit 1, the Press Release attached hereto as Exhibit 2, the Press Release attached to Amendment No. 6 as Exhibit 2, the FCC Letter attached to Amendment No. 6 as Exhibit 3, the Letter to the Board attached to Amendment No. 5 as Exhibit 2, the April 3 Press Release attached to Amendment No. 5 as Exhibit 3, the Demand Letter attached to Amendment No. 4 as Exhibit 2, the March 20 Press Release attached to Amendment No. 4 as Exhibit 3, the March 12 Press Release attached to Amendment No. 3 as Exhibit 2, the FCC Letter attached to Amendment No. 3 as Exhibit 3, the Press Release attached to Amendment No. 2 as Exhibit 2, the Stockholder Letter attached to Amendment No. 1 as Exhibit 2 and the Press Release attached to Amendment No. 1 as Exhibit 3, neither the Reporting Persons nor, to the best of the Reporting Persons’ knowledge, any person named on Schedule A hereto, has any contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer, including but not limited to, transfer or voting of any of the securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies.

The following documents are filed as exhibits:

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: April 11, 2013

EXHIBIT INDEX

SCHEDULE A

EXECUTIVE OFFICERS AND DIRECTORS OF CERTAIN REPORTING PERSONS

The following is a list of the executive officers and directors of certain Reporting Persons, setting forth the present principal occupation or employment and the name, principal business and address of any corporation or other organization in which such employment is conducted for each such person. The current business address of each such person is JP Morgan Chase Tower, 600 Travis, Suite 6800, Houston, TX 77002. All executive officers and directors listed below are citizens of the United States of America.

Exhibit 1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the Class A Common Stock of Clearwire Corporation and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement this 11^th day of April, 2013.

Exhibit 2

FOR IMMEDIATE RELEASE:

CONTACT:     Jeffrey Birnbaum, (202)661-6367, JBirnbaum@BGRPR.com

Crest Files Proxy Statement to Oppose Sprint-Clearwire Merger

HOUSTON, April 10, 2013 – Crest Financial Limited, the largest minority shareholder of Clearwire Corporation (NASDAQ: CLWR), today filed a preliminary proxy statement that, when cleared by the Securities and Exchange Commission, will be used to urge Clearwire stockholders to reject the proposed merger with Sprint Nextel Corporation.

In the preliminary proxy statement, Crest reiterates that it opposes the Sprint-Clearwire merger because it believes that “it would be better for Clearwire to remain a stand-alone company” because the Sprint offer of $2.97 in cash per share is inadequate – based on several measures – and was devised in a way that unfairly disadvantages minority stockholders.

“A vote ‘AGAINST’ each of the Clearwire Special Meeting Proposals would send a firm message to the Clearwire Board and Sprint that Clearwire must pursue a business strategy that creates value for all Clearwire stockholders – not just Sprint,” the preliminary proxy statement says.

Crest has hired the proxy-solicitation firm D. F. King & Co., Inc. to help it oppose the proposed Sprint-Clearwire merger . Crest has also filed a lawsuit in Delaware against Sprint, Clearwire and the directors of Clearwire because Crest believes that the defendants breached their fiduciary duties by scheming to extract value from Clearwire at the expense of the minority stockholders. In addition, Crest has petitioned the Federal Communications Commission in Washington, D.C., to stop the proposed Softbank-Sprint and Sprint-Clearwire mergers because they would treat minority stockholders of Clearwire unfairly and the mergers would not be in the public’s best interest.

“The filing of Crest’s proxy statement is the next step in our ongoing effort to block Sprint’s unfair merger offer and we are optimistic that we can do so,” said David Schumacher, general counsel of Crest. “We look forward to the SEC clearing our preliminary proxy statement so that we can begin educating Clearwire shareholders in earnest about the disadvantages of the Sprint offer and the alternative future for Clearwire and its valuable trove of wireless spectrum.”

The preliminary proxy statement can be found at http://www.dfking.com/clwr.

# # #

About Crest Financial Limited

Crest Financial Limited is a limited partnership under the laws of the State of Texas. Its principal business is investing in securities.

Important Legal Information

On April 10, 2013, Crest Financial Limited and Crest Investment Company (collectively, the “Participants”) filed with the Securities and Exchange Commission (the “SEC”) a preliminary proxy statement and accompanying proxy card relating to Participants’ intention to solicit proxies from the stockholders of Clearwire Corporation (“Clearwire”) in connection with a special meeting of such stockholders to be held to vote upon the proposed transaction between Clearwire and Sprint-Nextel Corporation (the “Preliminary Proxy Statement”). The Preliminary Proxy Statement is available at no charge on the website of the Participant’s proxy solicitor at http://www.dfking.com/clwr and on the SEC’s website at http://www.sec.gov. The Participants intend to file with the SEC a definitive proxy statement and accompanying proxy card in connection with such proxy solicitation. When completed, any such definitive proxy statement and proxy card will be furnished to some or all of the stockholders of Clearwire and will, along with other relevant documents, be available at no charge on the website of the Participant’s proxy solicitor at http://www.dfking.com/clwr and on the SEC’s web site at http://www.sec.gov. In addition, the Participants will provide copies of the definitive proxy statement and accompanying proxy card (when available) at no charge upon request. Information relating to the Participants in such proxy solicitation is contained in the Preliminary Proxy Statement. STOCKHOLDERS OF CLEARWIRE ARE ADVISED TO READ THE PRELIMINARY PROXY STATEMENT, WHICH IS AVAILABLE NOW, AND ANY DEFINITIVE PROXY STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION, INCLUDING ADDITIONAL INFORMATION RELATED TO THE PARTICIPANTS IN ANY SUCH SOLICITATION.

Forward-looking Statements

Certain statements contained herein are forward-looking statements including, but not limited to, statements that are predications of or indicate future events, trends, plans or objectives. Undue reliance should not be placed on such statements because, by their nature, they are subject to known and unknown risks and uncertainties. Forward-looking statements are not guarantees of future activities and are subject to many risks and uncertainties. Due to such risks and uncertainties, actual events may differ materially from those reflected or contemplated in such forward-looking statements. Forward-looking statements can be identified by the use of the future tense or other forward-looking words such as “believe,” “expect,” “anticipate,” “intend,” “plan,” “should,” “may,” “will,” believes,” “continue,” “strategy,” “position” or the negative of those terms or other variations of them or by comparable terminology.

SOURCE:     Crest Financial Limited