Exhibit 99.3

CONSENT OF OCEAN TOMO, A PART OF J.S. HELD

AltC Acquisition Corp.

10 East 53^rd Street

17^th Floor

New York, NY 10022

Board of Directors of AltC Acquisition Corp:

Ocean Tomo, a Part of J.S. Held, hereby consents to the inclusion of (i) summaries of and excerpts from our fairness opinion (the “Opinion”), dated July 11, 2023, to the Board of Directors of AltC Acquisition Corp. (“AltC”) in the filing of the Registration Statement on Form S-4 of AltC that is being filed on or promptly after the date hereof with the Securities and Exchange Commission (the “Registration Statement”), including, (A) the description of certain financial analyses underlying the Opinion and (B) certain terms of our engagement by AltC, and (ii) the Opinion as Annex H to the Registration Statement .

Notwithstanding the foregoing, it is understood that our consent is being delivered solely in connection with the filing of the above–mentioned version of the Registration Statement and that our opinions are not to be used, circulated, quoted or otherwise referred to in whole or in part in any registration statement (including any subsequent amendments to the above–mentioned Registration Statement), proxy statement/prospectus or any other document, except in accordance with our prior written consent. In giving such consent, we do not admit that we come within the category of persons whose consent is required under, and we do not admit that we are “experts” for purposes of, the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

/s/ Gregory Campanella

Gregory Campanella

Managing Director

Ocean Tomo, a Part of J.S. Held