Constellation Acquisition (CSTAF) lifts sponsor promissory note principal to $5.25M

Rhea-AI Filing Summary

Constellation Acquisition Corp I entered into a second amendment to an existing unsecured promissory note with its sponsor, Constellation Sponsor LP. The principal on the note was increased by $3,000,000, raising the total from $2,250,000 to $5,250,000. The note bears no interest and matures when the company closes its initial business combination, providing additional sponsor funding to support the special purpose acquisition company until it completes a deal.

8-K Event Classification

3 items: 1.01, 2.03, 9.01

3 items

Item 1.01 Entry into a Material Definitive Agreement Business

The company signed a significant contract such as a merger agreement, credit facility, or major partnership.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement Financial

The company incurred a new significant debt or off-balance-sheet obligation.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Understanding 8-K Material Events →

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 18, 2026

CONSTELLATION ACQUISITION CORP I

(Exact name of registrant as specified in its charter)

Cayman Islands		001-39945		98-1574835
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

1290 Avenue of the Americas 10th Floor New York, NY		10104
(Address of principal executive offices)		(Zip Code)

(212) 983-1602

Registrant’s telephone number, including area code

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Class A ordinary shares, par value $0.0001 per share		CSTAF		OTCID Basic Market
Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50		CSTWF		OTCID Basic Market
Units, each consisting of one Class A ordinary share and one-third of one redeemable warrant		CSTUF		OTCID Basic Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement.

On January 29, 2024, Constellation Acquisition Corp I, a Cayman Islands exempted company (the “Company”), issued an unsecured promissory note (the “Promissory Note”) in the principal amount of $1,660,000 to Constellation Sponsor LP, a Delaware limited partnership, bearing no interest and maturing once the Company closes its initial business combination. On June 5, 2025, the Company amended the promissory note, to increase the principal amount by $590,000 from $1,660,000 to $2,250,000. On March 18, 2026, the Company further amended the Promissory Note (the “Second Amendment”), to increase the principal amount by $3,000,000 from $2,250,000 to $5,250,000. Unless otherwise set forth in the Second Amendment, all other provisions of the Promissory Note remain in full force and effect.

The foregoing description of the Second Amendment is qualified in its entirety by reference to the full text of the Second Amendment, which is incorporated by reference herein and filed herewith as Exhibit 10.1.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The disclosure contained in Item 1.01 of this Current Report on Form 8-K is incorporated by reference in this Item 2.03.

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Item 9.01. Exhibits.

(d) Exhibits

Exhibit No.		Exhibit
10.1		Second Amendment to the Promissory Note, dated March 18, 2026, between Constellation Acquisition Corp I and Constellation Sponsor LP.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

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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 hereunto duly authorized. 

	CONSTELLATION ACQUISITION CORP I
Dated: March 19, 2026	By:	/s/ Chandra R. Patel
		Chandra R. Patel
		Chief Executive Officer

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FAQ

What did Constellation Acquisition Corp I (CSTAF) change in its promissory note?

Constellation Acquisition Corp I amended its unsecured promissory note with Constellation Sponsor LP, raising the principal from $2,250,000 to $5,250,000. This second amendment adds $3,000,000 of sponsor funding, supporting the SPAC until it completes its initial business combination.

Who is the lender under Constellation Acquisition Corp I’s amended promissory note?

The lender is Constellation Sponsor LP, a Delaware limited partnership affiliated with the SPAC. It provides an unsecured, no-interest promissory note that now totals $5,250,000, maturing when Constellation Acquisition Corp I closes its initial business combination transaction.

Does the Constellation Acquisition Corp I promissory note bear interest?

No, the unsecured promissory note issued to Constellation Sponsor LP bears no interest. The company can access up to $5,250,000 of principal, with repayment due upon completion of its initial business combination, rather than accruing periodic interest expense over time.

When does Constellation Acquisition Corp I’s amended promissory note mature?

The promissory note matures when Constellation Acquisition Corp I closes its initial business combination. This ties repayment of the now $5,250,000 principal directly to the successful completion of a merger or similar transaction, aligning the note’s timeline with the SPAC’s core objective.

What SEC items did Constellation Acquisition Corp I report related to this note amendment?

The company reported the second amendment under Item 1.01, Entry into a Material Definitive Agreement, and referenced it under Item 2.03 concerning creation of a direct financial obligation. The full amendment is filed as Exhibit 10.1 to the current report.

Filing Exhibits & Attachments

5 documents

Agreements & Contracts

• EX-10.1 SECOND AMENDMENT TO THE PROMISSORY NOTE, DATED MARCH 18, 2026, BETWEEN CONSTELLA 11.9 KB

Other Documents

• EX-101 XBRL SCHEMA FILE 4.1 KB
• EX-101 XBRL DEFINITION FILE 26.7 KB
• EX-101 XBRL LABEL FILE 37.1 KB
• EX-101 XBRL PRESENTATION FILE 25.4 KB