NT 10-K Late Filing Notice for Constellation Acquisition Corp I

NT 10-K 1 ea0284269-nt10k_constell1.htm NOTIFICATION OF LATE FILING

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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FORM 12b-25

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NOTIFICATION OF LATE FILING

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| (Check one): | ☒ Form 10-K ☐ Form 20-F ☐ Form 11-K ☐ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR |

For Period Ended: December 31, 2025

| | ☐ | Transition Report on Form 10-K |

| | ☐ | Transition Report on Form 20-F |

| | ☐ | Transition Report on Form 11-K |

| | ☐ | Transition Report on Form 10-Q |

For the Transition Period Ended:

| Nothing in this form shall be construed to imply that the Commission has verified any information contained herein. |

If the notification relates to a portion of the filing checked above,
identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

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| CONSTELLATION ACQUISITION CORP I |
Full Name of Registrant

| |
Former Name if Applicable

| 1290 Avenue of the Americas 10th Floor |
Address of Principal Executive Office (Street and Number)

| New York, NY 10104 |
City, State and Zip Code

PART II — RULES 12b-25(b) AND (c)

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If the subject report could not be filed without unreasonable effort
or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

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| | (a) | The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense; |
| ☒ | (b) | The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-CEN or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and |
| | (c) | The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable |

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PART III — NARRATIVE

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State below in reasonable detail why Forms 10-K, 20-F,
11-K, 10-Q, 10-D, N-CEN, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

Constellation Acquisition Corp I (the “ Company ”)
is filing this Notification of Late Filing on Form 12b-25 with respect to its Annual Report on Form 10-K for the annual period ended December
31, 2025 (the “ Form 10-K ”). The Company has determined that it is unable to file its Form 10-K within the prescribed
time period without unreasonable effort or expense because the review and finalization of the financial information and other disclosures
required to be included in the Form 10-K. The Company anticipates filing the Form 10-K as soon as practicable and no later than 15 calendar
days following the prescribed due date, in accordance with Rule 12b-25 of the Securities and Exchange Act of 1934, as amended.

PART IV — OTHER INFORMATION

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| (1) | Name and telephone number of person to contact in regard to this notification |

| Chandra R. Patel | | 212 | | 983-1602 |
| (Name) | | (Area Code) | | (Telephone Number) |

| (2) | Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s). ☒ Yes ☐ No |

| (3) | Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof? |

☒
Yes ☐ No

If so, attach an explanation of the anticipated
change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be
made.

For 2024, the Company reported a net loss of approximately
$248,000, which included a loss from operations of approximately $1,600,000, partially offset by interest earned on investments of approximately
$1,300,000 and a gain from the change in fair value of warrant liabilities of approximately $47,000.

For 2025, the Company expects to report a net loss
of approximately $3,200,000, which included a loss from operations of approximately $1,100,000 and a loss from the change in fair value
of warrant liabilities of approximately $2,300,000, partially offset by interest earned on investments of approximately $105,000.

| | CONSTELLATION ACQUISITION CORP I | |
| | (Name of Registrant as Specified in Charter) | |

has caused this notification to be signed on its behalf
by the undersigned hereunto duly authorized.

| Date: April 1, 2026 | CONSTELLATION ACQUISITION CORP I | | |
| | | | |
| | By: | /s/ Chandra R. Patel | |
| | | Name: | Chandra R. Patel |
| | | Title: | Chief Executive Officer |