UMC (UMC) directors, officers face new U.S. insider disclosure rules

Rhea-AI Filing Summary

United Microelectronics Corporation filed a report explaining new U.S. disclosure requirements for its leaders. Due to the Holding Foreign Insiders Accountable Act, effective from March 18, 2026, the company’s directors and officers must publicly report their ownership of, and transactions in, UMC equity securities under Section 16(a) of the U.S. Securities Exchange Act of 1934.

These insider ownership and trading disclosures will be available on the U.S. SEC’s EDGAR website, giving investors a direct view into how key insiders hold and trade UMC stock.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

March 26, 2026

(Commission File Number: 001-15128)

United Microelectronics Corporation

(Translation of registrant’s name into English)

No. 3 Li-Hsin 2nd Road,

Hsinchu Science Park,

Hsinchu, Taiwan, R.O.C.

(Address of principal executive office)

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  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): 

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, thereto duly authorized.

United Microelectronics Corporation
By:	Chitung Liu
Name:	Chitung Liu
Title:	CFO

Date: March 26, 2026

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EXHIBIT INDEX

Exhibit		Description
99.1		6K on 03/26/2026

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www.umc.com

Exhibit

Exhibit Description

99.1 Announcement on 2026/03/26: Announcement on Disclosures by Directors and Officers pursuant to the U.S. Securities Exchange Act

Exhibit 99.1

Announcement on Disclosures by Directors and Officers pursuant to the U.S. Securities Exchange Act

1. Date of occurrence of the event: 2026/03/26

2. Company name: UNITED MICROELECTRONICS CORPORATION

3. Relationship to the Company (please enter “head office” or “subsidiaries”): head office

4. Reciprocal shareholding ratios: N/A

5. Cause of occurrence: N/A

6. Countermeasures: N/A

7. Any other matters that need to be specified (the information disclosure also meets the requirements of Article 7, subparagraph 9 of the Securities and Exchange Act Enforcement Rules, which brings forth a significant impact on shareholders rights or the price of the securities on public companies.):

According to the “Holding Foreign Insiders Accountable Act”, enacted by U.S. Congress on December 18, 2025, from March 18, 2026, the Company’s directors and officers will be required to disclose their ownership of and transactions in the Company’s equity securities in accordance with Section 16(a) of the U.S. Securities Exchange Act of 1934. For related disclosures, please visit the U.S. SEC’s EDGAR website: https://www.sec.gov/edgar/browse/?CIK=1033767&owner=only

FAQ

What did UMC (UMC) announce in this Form 6-K?

United Microelectronics Corporation announced that, starting March 18, 2026, its directors and officers must disclose their UMC share ownership and transactions under U.S. Section 16(a) rules, following the Holding Foreign Insiders Accountable Act.

When do UMC directors and officers start Section 16(a) reporting?

UMC directors and officers are required to begin Section 16(a) ownership and transaction reporting from March 18, 2026. This timing follows enactment of the Holding Foreign Insiders Accountable Act on December 18, 2025 by the U.S. Congress.

Which law triggers the new UMC insider disclosure requirements?

The new disclosure requirements for UMC insiders arise from the Holding Foreign Insiders Accountable Act, enacted by the U.S. Congress on December 18, 2025. It subjects UMC directors and officers to U.S. Section 16(a) reporting obligations.

Where can investors find UMC insider trading disclosures?

Investors can access UMC directors’ and officers’ ownership and trading disclosures on the U.S. SEC’s EDGAR website. The company directs readers to its EDGAR CIK page, where Section 16(a) filings will appear under the specified CIK number.

Who within UMC is affected by the new U.S. reporting rules?

The new U.S. reporting rules affect UMC’s directors and officers at the head office. They must disclose their holdings of, and transactions in, United Microelectronics Corporation equity securities in compliance with Section 16(a) of the U.S. Securities Exchange Act.

Does UMC consider this disclosure change significant for shareholders?

UMC notes the disclosure also meets Article 7, subparagraph 9 of the Securities and Exchange Act Enforcement Rules, indicating it regards the change as having a significant potential impact on shareholder rights or the market price of its securities.

Filing Exhibits & Attachments

1 document

Press Releases

• EX-99.1 EX-99.1 9.1 KB