SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

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

of the Securities Exchange Act of 1934

For the Month of October 2018

Commission File Number 1-15028

China Unicom (Hong Kong) Limited

(Exact Name of Registrant as Specified in Its Charter)

75/F, The Center,

99 Queen’s Road Central, Hong Kong

(Address of principal executive offices)

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

Form 20-F  ☒            Form 40-F  ☐

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

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

(Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.)

Yes  ☐            No  ☒

(If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):82-            .)

EXHIBITS

FORWARD-LOOKING STATEMENTS

This announcement contains certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Such forward-looking statements may include, without limitation, statements relating to (i) the Company’s plans and strategies and the ability to successfully execute these plans and strategies, including those in connection with mergers and acquisitions and capital expenditures; (ii) the Company’s plans for network expansion, including those in connection with the build-out of mobile services and network infrastructure; (iii) the Company’s competitive position, including the ability to upgrade and expand existing networks and increase network efficiency, to improve existing services and offer new services, to develop new technological applications and to leverage the Company’s position as an integrated telecommunications operator and expand into new services and markets; (iv) the Company’s future business condition, including future financial results, cash flows, financing plans and dividends; (v) the future growth of market demand of, and opportunities for, the Company’s new and existing products and services; and (vi) future regulatory and other developments in the PRC telecommunications industry.

The words “anticipate”, “believe”, “could”, “estimate”, “intend”, “may”, “seek”, “will” and similar expressions, as they relate to the Company, are intended to identify certain of these forward-looking statements. The Company does not intend to update any of these forward-looking statements and are under no obligation to do so.

The forward-looking statements contained in this announcement are, by their nature, subject to significant risks and uncertainties. In addition, these forward-looking statements reflect the Company’s current views with respect to future events and are not a guarantee of the Company’s future performance. Actual results may differ materially from those expressed or implied in the forward-looking statements as a result of a number of factors, including, without limitation:

Please also see the “Risk Factors” section of the Company’s latest Annual Report on Form 20-F, as filed with the U.S. Securities and Exchange Commission.

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.

Exhibit 1

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

CHINA UNICOM (HONG KONG) LIMITED

中國聯合網絡通信(香港)股份有限公司

(Incorporated in Hong Kong with limited liability)

(Stock Code: 0762)

Profit Alert

This announcement is made by China Unicom (Hong Kong) Limited (the “Company”, together with its subsidiaries, the “Group”) pursuant to Rule 13.09 of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited and the Inside Information Provisions under Part XIVA of the Securities and Futures Ordinance (Chapter 571 of the Laws of Hong Kong).

In the third quarter of 2018, the Group continued to implement the national policy of “speed upgrade and tariff reduction”, and cancelled domestic handset data “roaming” fees with effect from 1 July. In the first half of the year, the Group prepared in advance by strengthening data traffic operation, optimising tariff packages and strengthening efforts to promote heavy data packages, in order to facilitate a smooth transition for customers and strive to achieve win-win leveraging price elasticity. It mitigated the downward pressure on the Group’s mobile service revenue in the third quarter resulting from the cancellation of domestic handset data “roaming” fees.

In the first three quarters of 2018, the Group insisted on deepening the implementation of the Strategy of Focus, Innovation and Cooperation and fully accelerated the establishment of China Unicom’s “Five New”. It gradually sped up the pace in driving Internet-oriented operations, while its efforts in mixed-ownership reform started delivering notable enhancement in growth momentum, quality and efficiency. In this period, overall service revenue is expected to be approximately RMB 200,013 million, up by 6.5% year-on-year. Mobile service revenue is expected to be approximately RMB 125,424 million, up by 7.2% year-on-year. Fixed-line service revenue is expected to be approximately RMB 73,223 million, up by 5.2% year-on-year. The profit attributable to the equity shareholders of the Company is expected to be approximately RMB 8,780 million, up significantly by 116.6% year-on-year. It included an increase of RMB 1,474 million in the Group’s share of net profit of associates resulting from the change in the Group’s shareholding percentage in China Tower after its listing and new share issuance.

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Market competition may intensify cyclically in the fourth quarter this year. The Group will actively cope with challenges and persistently deepen the execution of its Strategy of Focus, Innovation and Cooperation. It will accelerate the establishment of China Unicom’s “Five New” and persevere in the implementation of the Internet-oriented operation. Seizing opportunities afforded by the mixed-ownership reform, the Group will deepen strategic cooperation and further advance the system and mechanism reform, accelerating the delivery of benefits from the reform and comprehensively enhancing the Group’s overall competitive strengths. It will appropriately step up investments in innovative businesses and talents development, in order to proactively nurture future growth engines and drive high-quality sustainable growth in full-force.

Caution Statement

The Board wishes to remind shareholders and investors in the Company that the above estimated financial data are based on the preliminary assessment made by the management of the Company with reference to the information currently available and the unaudited management accounts of the Group, and have not been reviewed or audited by the auditors of the Company. Information to be disclosed in the announcement of the Company’s key financial and performance indicators for the first three quarters of 2018 on 22 October 2018 shall prevail. The Company’s shareholders and investors are cautioned not to unduly rely on the above data. In the meantime, the Company’s shareholders and investors are advised to exercise caution in dealing in the securities of the Company.

Hong Kong, 21 October 2018

Certain statements contained in this announcement may be viewed as “forward-looking statements” within the meaning of Section 27A of the U.S. Securities Act of 1933 (as amended) and Section 21E of the U.S. Securities Exchange Act of 1934 (as amended). Such forward-looking statements are subject to known and unknown risks, uncertainties and other factors, which may cause the actual performance, financial condition or results of operations of the Company to be materially different from any future performance, financial condition or results of operations implied by such forward looking statements. In addition, we do not intend to update these forward-looking statements. Further information regarding these risks, uncertainties and other factors is included in the Company’s most recent Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission (the “SEC”) and in the Company’s other filings with the SEC.

As at the date of this announcement, the board of directors of the Company comprises:

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