Atlas Investissement SAS → MILLICOM INTERNATIONAL CELLULAR SA MLCMF

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following: On June 18, 2026, Atlas Investissement amended the New Equity Derivative Transaction (as defined and described in Amendment No. 27 to the Schedule 13D) through the entry into an amendment agreement (the "Amendment Agreement") relating to the Amended Equity Derivative Transaction Agreements (as defined and described in Amendment No. 27 to the Schedule 13D) with an unaffiliated third party financial institution (the "Bank"). Under the New Equity Derivative Transaction as amended by the Amendment Agreement, Atlas Investissement expects to purchase up to an additional 1,250,000 Common Shares on June 29, 2026. The actual timing and the number of Common Shares to be purchased under such transaction will be determined based on the hedging position of the Bank in accordance with certain parameters of the Amended Equity Derivative Transaction Agreements. The Amendment Agreement also increased the applicable maximum equity notional amount under the Amended Equity Derivative Transaction Agreements, which is intended to help Atlas Investissement purchase the maximum number of Common Shares under the Original Equity Derivative Transaction (as defined and described in Amendment No. 27 to the Schedule 13D) and the New Equity Derivative Transaction as planned. In addition, the Amendment Agreement amended the final maturity date under the Amended Equity Derivative Transaction Agreements to June 29, 2026. Except as described in this Item 4, the material terms of the Amended Equity Derivative Transaction Agreements governing the Original Equity Derivative Transaction and the New Equity Derivative Transaction remain the same as previously disclosed in Amendment Nos. 26 and 27 to the Schedule 13D. The foregoing description of the Amendment Agreement is qualified in its entirety by reference to the text of the Amendment Agreement, a copy of which is filed as exhibit to this Amendment No. 28 and incorporated herein by reference. Separately from the above, on June 23, 2026, Atlas Investissement has irrevocably elected cash settlement for the three European-style call spread option transactions contemplated under each of the respective Letter Agreements on Share Option Transaction (as defined and described in Amendment No. 20 to the Schedule 13D).