HUNTSVILLE, Ala. - (July 15, 2022)— ADTRAN Holdings, Inc. (NASDAQ: ADTN and FSE: QH9) (“ADTRAN Holdings” or the “Company”) today announced the closing of its business combination with ADVA Optical Networking SE (FSE: ADV) (“ADVA”). The companies received all necessary regulatory approvals and shareholder consent, making closure possible. ADTRAN Holdings is now the parent company of ADTRAN, Inc. (“ADTRAN”) through the merger of ADTRAN with and into a wholly-owned subsidiary of ADTRAN Holdings. Additionally, tendered ADVA shares were exchanged for shares of ADTRAN Holdings today, making ADTRAN Holdings the majority shareholder of ADVA.

Tom Stanton, Chairman and CEO of ADTRAN Holdings said, “This is an exciting day for both companies. With closing now behind us, we can focus on the final steps that will allow us to fully integrate these companies, creating a driving force within the industry. We believe that the combination of our exceptional talent, industry-leading solution portfolios, and vision for innovation, positions us as a global trusted leader for service provider, government, and enterprise customers and will provide a firm foundation for our success moving forward.”

As already announced, the Company intends to enter into either a domination agreement or a domination and profit and loss transfer agreement to further drive integration, which will be a further step in making the Company a global leader in end-to-end fiber networking. With an addressable market of $13.7 billion the combined company will offer an unparalleled product portfolio ranging from in-home connectivity and business access solutions to optical core transport.

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About ADTRAN Holdings, Inc.

ADTRAN Holdings, Inc. is the parent company of ADTRAN, a wholly owned subsidiary and a leading global provider of open, disaggregated networking and communications solutions. ADTRAN Holdings is also the largest shareholder of ADVA, aEuropean telecommunications vendorthat provides network equipment for data, storage, voice, and video services.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the United States Securities Exchange Act of 1934, as amended. You can generally identify forward-looking statements by the use of forward-looking terminology such as "anticipate," "believe," "continue," "could," "estimate," "expect," "explore," "evaluate," "intend," "may," "might," "plan," "potential," "predict," "project," "seek," "should," or "will," or the negative thereof or other variations thereon or comparable terminology. These forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond Adtran and ADVA’s control.

These forward-looking statements include, but are not limited to, statements regarding benefits of the proposed business combination, integration plans and expected synergies, and anticipated future growth, financial and operating performance and results. Forward-looking statements involve risks and uncertainties that may cause actual results to be materially different from the results predicted or expected. No assurance can be given that these forward-looking statements will prove accurate and correct, or that projected or anticipated future results will be achieved. Factors that could cause actual results to differ materially from those indicated in any forward looking statement include, but are not limited to: the expected timing and likelihood of the completion of the contemplated business combination, including the timing, receipt and terms and conditions of any required governmental and regulatory approvals of the contemplated business combination that could reduce anticipated benefits or cause the parties to abandon the transaction; the occurrence of any event, change or other circumstances that could give rise to the termination of the business combination agreement; the ability to successfully complete the proposed business combination; regulatory or other limitations imposed as a result of the proposed business combination; the success of the business following the proposed business combination; the ability to successfully integrate the Adtran and ADVA businesses; the possibility that Adtran stockholders may not approve the business combination agreement or that the requisite number of ADVA shares may not be tendered in the public Offer; the risk that the parties may not be able to satisfy the conditions to closing of the proposed business combination in a timely manner or at all; risks related to disruption of management time from ongoing business operations due to the proposed business combination; the risk that the publicity surrounding or consummation of the proposed business combination could have adverse effects on the market price of Adtran's common stock or ADVA's common shares or the ability of Adtran and ADVA to retain customers, retain or hire key personnel, maintain relationships with their respective suppliers and customers, and on their operating results and businesses generally; the risk that Acorn HoldCo may be unable to achieve expected synergies or that it may take longer or be more costly than expected to achieve those synergies; the risk of fluctuations in revenue due to lengthy sales and approval process required by major and other service providers for new products; the risk posed by potential breaches of information systems and cyber-attacks; the risks that Adtran, ADVA or the post-combination company may not be able to effectively compete, including through product improvements and development; and such other factors as are set forth in ADVA's annual and interim financial reports made publicly available and Adtran's and Acorn HoldCo's public filings made with the SEC from time to time, including but not limited to those described under the headings "Risk Factors" and "Forward-Looking Statements" in Adtran's Form 10-K for the fiscal year ended December 31, 2020 and Adtran's Form 10-Q for the quarterly period ended September 30, 2021, which are available via the SEC's website at www.sec.gov.

The foregoing list of risk factors is not exhaustive. These risks, as well as other risks associated with the contemplated business combination, are more fully discussed in the proxy statement/prospectus and the offering prospectus that are included in the Registration Statement on Form S-4 that has been filed by Acorn HoldCo with the SEC and in the Offer Document that has been filed by Acorn HoldCo with BaFin and that has been published in connection with the contemplated business combination, as well as in any prospectuses or supplements. In light of these risks, uncertainties and assumptions, the events described in the forward-looking statements might not occur or might occur to a different extent or at a different time than Adtran, ADVA or Acorn HoldCo has described. All such factors are difficult to predict and beyond our control. All forward-looking statements included in this document are based upon information available to Adtran, ADVA and Acorn HoldCo on the date hereof, and each of Adtran, ADVA and Acorn HoldCo disclaims and does not undertake any obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.