Given the numerous questions we receive about supply chain impacts, we want to address the ongoing challenges we’ve faced, particularly equipment delays in our EV charging business. Although these delays impacted some projects, we are committed to proactively addressing and finding effective solutions for these challenges. One such solution is our previously announced collaboration with Autel, who offers a full line of high-quality charging solutions in a timely manner. Within our Infrastructure segment, backlog represents the remaining project revenues to be recognized in the future. Backlog levels can fluctuate quarter-to-quarter based on seasonality and completion or booking of large, longer-term projects, specifically within our electrical services business as the duration of its projects can last up to 24 months.
Our backlog after considering our recognized revenue in the quarter increased slightly to approximately $139 million at September 30, 2023, compared to $138 million at the end of the second quarter of 2023, which excluded the recent Greenspeed acquisition. The levels of backlog within our electrical services business exhibit some volatility primarily attributable to the size and duration of the contracts. Our EV charging infrastructure business accounted for 42% of the $139 million, showing significant growth compared to the third quarter of last year when our EV backlog was minimal. We anticipate earning approximately 25% of the $139 million backlog within revenues in the fourth quarter of 2023 and most of the remaining in 2024. Let’s move to Slide 8 to discuss adjusted EBITDA.
We focus on adjusted EBITDA as the closest measure of our true operating performance. For the third quarter, adjusted EBITDA loss was $0.6 million compared with adjusted EBITDA loss of $1.7 million in the prior year period, mainly driven by improvements within Infrastructure. During the third quarter, our Infrastructure segment’s adjusted EBITDA of $3.7 million increased year-over-year and reached the highest point in the last five quarters, primarily due to projects nearing the end of their life cycle and coming in under budget as a result of our operational experience and tight project management. In our Telecommunications segment, adjusted EBITDA experienced a decrease, primarily attributed to the decline in gross profit due to decrease in voice volume.
Within corporate, adjusted EBITDA loss increased during the third quarter compared to the prior year period, primarily due to approximately $0.5 million of nonrecurring legal expenses in the current period. Furthermore, in the third quarter, there was an increase in overall SMB cost to support the growth associated with their transition to a public company structure. We continue to prudently manage our costs while balancing the necessary investments needed to grow the company. In summary, I am pleased with the adjusted EBITDA results we delivered in the third quarter of 2023, which are the best since we joined the NASDAQ in April of 2022. Turning to Slide 9. Looking at the full P&L for the quarter, we saw strong growth in gross profit and gross margin.
Operating expenses, including G&A, SMB and professional services collectively were higher year-over-year, which reflect our investments in technology, people, processes and capabilities to foster growth across all of our businesses and support the corporate structure. As we have stated previously, over the past 18 months, we were actively hiring for both Charge corporate and our EV charging infrastructure business. In thinking about ongoing SMB spend levels, we have established a foundation. And from this point forward, our hiring focus will be targeted on supporting organic growth. We closed the third quarter with $57.2 million of cash, cash equivalents and marketable securities, most of which is expected to be used for operations and debt service.
We continue to have active productive discussions with our senior lender to meet our upcoming obligations. As we finish the third quarter and look ahead, I am encouraged by our trends in adjusted EBITDA and backlog as well as the integration amongst our subsidiaries and the acquisition of Greenspeed. We reiterate our anticipation of positive adjusted EBITDA for the first quarter of 2024, and we believe we will deliver positive adjusted EBITDA for the full year of 2024. At this time, I will turn today’s webcast to the operator for our Q&A session.
Operator: As a reminder, today’s questions were previously solicited. Our first set of questions comes from Tate Sullivan with Maxim. What other types of electrical contracting jobs does Charge Enterprises work on?
Craig Denson: Good morning Tate. Charge Enterprises offers a diversified portfolio of services in the electrical area. Some of our largest projects are with local and state government entities, such as the project we did with the restoration of the New Jersey State House, which is nearing completion. We also work with universities, health care systems, pharmaceutical facilities and stadiums to name a few. The recent acquisition of Greenspeed expanded our service reach to include commercial lighting, solar and energy storage solutions.
