Overall, our business performed well in the third quarter as we witnessed some encouraging trends, primarily in our aviation segment where commercial passenger activity continue to increase both domestically with activity climbing to more than 80% of its pre-pandemic levels and internationally where easing travel restrictions have led to increased activity in Europe and Asia.
Before I walk through our third quarter results, please note that the following figures exclude the impact of non-operational items netting only $1 million this quarter, which principally related to acquisition divestiture and restructuring related adjustments in expenses.
Adjusted third quarter net income and earnings per share were $23 million and $0.36 per share, respectively.
Adjusted EBITDA for the third quarter was $63 million.
With third quarter consolidated volume up 9% sequentially and 23% year-over-year.
We generated positive cash flow from operations of $83 million during the third quarter contributing to our net cash position of $282 million.
This was our 14th consecutive quarter of positive operating cash flow totaling approximately $1.4 billion over such period.
Aviation segment volume was 1.7 billion gallons in the third quarter, an increase of 21% sequentially, consistent with the growth forecast provided on our second quarter call and an increase of 63% compared to the third quarter of 2020.
Volume in our marine segment for the third quarter was 4.8 million metric tons, an increase of 4% sequentially and 9% year-over-year.
Our land segment volume was 1.3 billion gallons or gallon equivalents during the third quarter.
That's practically flat sequentially, but an increase of 4% year-over-year.
Consolidated volume for the third quarter was 4.2 billion gallons or gallon equivalents, an increase of 9% sequentially and 23% year-over-year driven by the significant rebound in aviation activity.
Consolidated gross profit for the third quarter was $197 million, an increase of 7% sequentially and 3% year-over-year.
Our aviation segment contributed $113 million of gross profit in the third quarter.
That's up 28% sequentially and 19% year-over-year.
Our team in Afghanistan did an amazing job over the past 10 years.
The marine segment generated third quarter gross profit of $22 million down 4% sequentially and 31% year-over-year.
Our land segment delivered gross profit of $63 million in the third quarter, a seasonal decline of 15% sequentially and a decline of 4% year-over-year when excluding MultiService from last year's results.
Core operating expenses which exclude bad debt expense were $153 million in the third quarter.
Looking ahead to the fourth quarter, we expect core operating expenses excluding bad debt expense to be in the range of $156 million to $160 million.
Again, adjusted EBITDA was $63 million in the third quarter, that's up 6% sequentially but down slightly compared to last year's third quarter.
Interest expense in the third quarter was $10 million, which is effectively flat year-over-year and fourth quarter interest expense should be about the same in the range of $10 million to $11 million.
And our adjusted effective tax rate for the third quarter was just under 31% and we expect the fourth quarter effective tax rate to be about the same.
Despite rising prices and volume, we generated $83 million of operating cash flow during the third quarter, our 14th consecutive quarter of positive operating cash flow.
This further strengthen our balance sheet resulting in a net cash position of $282 million at quarter end at a total cash position of nearly $800 million.
We also repurchased 750,000 shares of our common stock during the quarter, demonstrating our continued commitment to drive additional shareholder value through both buybacks and dividends.
We generated strong operating cash flow in a sharply rising price environment contributing to an ending cash position of nearly $800 million setting us up well for the Flyers acquisition, but also for the additional growth opportunities ahead.
The remaining $100 million we paid in two equal $50 million instalments upon the first and second anniversaries of closing.
Again, we had $796 million of cash at end of September, with the remainder to be drawn under our revolving credit facility.
The transaction is expected to be significantly accretive to margins, earnings per share and cash flow and is expected to close within 60 to 90 days subject to customary closing conditions, including regulatory approval.
Flyers which has been very successfully operated by the Dwelle family for decades is based in Auburn, California and distributes diesel, renewable fuels, lubricants and gasoline to more than 12,000 small to medium sized commercial and industrial and retail customers spanning 20 states.
Estimated volume for 2021 is $850 million gallons with forecasted 2021 revenue and gross profit of $2.4 billion and $135 million respectively.
Flyers are the national fleet fueling network consisting of approximately 200 card lock sites which are operated by Flyers and an additional 200 third-party sites, which are part of their national network.
Card locks are effectively unmanned fuel sites serving commercial trucking fleets providing 24 hour access 365 days per year.
While their card lock operation is clearly their largest segment, Flyers also operates a small retail distribution business which will expand the World Fuel network to more than 2,000 retail locations nationwide and they also operate a wholesale diesel and lubricants business.
These combined business activities represented less than 50% of total land gross profit back in 2019 before the start of the pandemic.
If you fast forward to our new run rate upon closing this transaction, these core activities will represent more than 80% of land gross profit and the overall land business will represent a greater percentage of our global franchise driving greater scale synergies and operating leverage.
The transaction will also expand our North American platform to more than 30,000 commercial and industrial customers, customers to whom we can support with options to purchase lower carbon renewable fuels.
While this will indeed be the largest acquisition in the history of our Company, the substantial cash flow we have generated over the past three to four years combined with the cash generated from the sale of MultiService last year allows us to complete this transaction largely with cash on hand, leaving us with a strong and liquid balance sheet post-acquisition to support organic growth as well as further investments in core business activities principally on North American land and global gas power and sustainability business providing a more exciting experience for our global team of nearly 5,000 professionals and driving greater value to our shareholders.

Summary:
Adjusted third quarter net income and earnings per share were $23 million and $0.36 per share, respectively.
Volume in our marine segment for the third quarter was 4.8 million metric tons, an increase of 4% sequentially and 9% year-over-year.