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FORM 6-K

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities Exchange Act of 1934

Commission File Number: 333-163336

For the month of November 2010.

NKSJ Holdings, Inc.

(Translation of registrant’s name into English)

26-1, Nishi-Shinjuku 1-chome

Shinjuku-ku, Tokyo 160-8338

Japan

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F      X            Form 40-F              

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):              

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):              

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Information furnished on this form:

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Revision of Forecasts of Financial Results for the first half fiscal year ending March 31, 2011

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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, thereunto duly authorized.

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[Note: This document is an unofficial English translation of the Japanese original.]

[English Translation]

November 2, 2010

To whom it may concern:

Revision of Forecasts of Financial Results for the first half fiscal year ending March 31, 2011

NKSJ Holdings, Inc. hereby revises forecasts of financial results for the first half fiscal year ending March 31, 2011, which were announced on May 20, 2010. Forecasts of financial results for the entire fiscal year ending March 31, 2011 are currently being processed and will be announced on November 19, 2010 along with an announcement of business results for the first half fiscal year.

Furthermore, yesterday, Ambac Financial Group, Inc., which is holding company whose affiliates provided financial guarantees, announced a possibility to file for bankruptcy. This possibility will have no influence on the business results of NKSJ Holdings.

(April 1, 2010 to September 30, 2010)

The revision is primarily due to an expected decrease in the amount of incurred losses, as compared to the previous forecasts, in connection with natural disasters recorded by two major subsidiaries, SOMPO JAPAN INSURANCE INC. (non-consolidated basis) and NIPPONKOA Insurance Co., Ltd. (non-consolidated basis).

(Reference) Revised forecasts of non-consolidated financial results for the first half fiscal year ending March 31, 2011

(Note for using forecasted information)

The forecasts included in this document are based on the currently available information and certain assumptions that we believe reasonable. Accordingly, the actual results may differ materially from those projected herein depending on various factors.

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Note Regarding Forward-looking Statements

This document includes “forward-looking statements” that reflect the information in relation to the NKSJ Holdings, Inc. (“NKSJ”). To the extent that statements in this document do not relate to historical or current facts, they constitute forward-looking statements. These forward-looking statements are based on the current assumptions and beliefs of NKSJ in light of the information currently available to NKSJ, and involve known and unknown risks, uncertainties and other factors. Such risks, uncertainties and other factors may cause the actual results, performance, achievements or financial position of NKSJ, as the case may be, to be materially different from any future results, performance, achievements or financial position expressed or implied by these forward-looking statements. NKSJ does not undertake or will not undertake any obligation to publicly update any forward-looking statements after the date of this document. Investors are advised to consult any further disclosures by NKSJ in their subsequent domestic filings in Japan and filings with, or submissions to, the U.S. Securities Exchange Commission pursuant to the U.S. Securities Exchange Act of 1934.

The risks, uncertainties and other factors referred to above include, but are not limited to, those below. The risks, uncertainties and other factors are also referred to in our domestic Quarterly Securities Reports.