Relative to the global office leasing market, JLL Research reported that activity in the fourth quarter was down 43% from a year earlier.
The United States saw a much sharper decline compared to the other regions with activity down 53%.
EMEA and Asia Pacific recorded decreases in activity of 39% and 25% respectively relative to last year.
Vacancy rates increased across all regions in the fourth quarter with a global vacancy rate now at 12.9%, the highest level since 2014.
Consolidated revenue fell 8% to $16.6 billion and fee revenue declined 14% to $6.1 billion in local currency.
We recorded adjusted EBITDA of $860 million, a decline of 24% from the prior year and adjusted diluted earnings per share of $9.46, which represented a decline of 34% from the prior year.
It is worth noting that despite the challenges of 2020, we were able to achieve a full year 14% adjusted EBITDA margin, which is within our long-term target range of 14% to 16%.
We also generated a record $1.1 billion in operating cash flow, testament to the strength of our business model and ability to navigate a downturn.
Consolidated revenue fell 12% to $4.8 billion and fee revenue declined 19% to $2 billion in local currency.
Adjusted EBITDA of $417 million represented a decline of 18% from the prior year, although adjusted EBITDA margin increased 50 basis point to 21.3% as reported, driven by cost mitigation initiatives and some government COVID programs.
Adjusted net income totaled $276 million for the quarter and adjusted diluted earnings per share totaled $5.29.
Our current approach is to operate within a reported net leverage range of 0.5 to 1.25 times, recognizing that there may be periods outside of this range due to seasonality and other short-term factors.
Any opportunity must meet our already rigorous standards specifically, they must be value-accretive acquisitions that are appropriately priced, have a strong cultural and strategic fit and generate a return on invested capital of at least 12%.
Over the long-term, we are committed to returning approximately 20% our free cash flow to shareholders.
We repurchased 100 million worth of shares at an average price of $111.
We have 100 million remaining on our existing repurchase authorization and the Board of Directors recently authorized an incremental 500 million share repurchase program for a total of $600 million.
Once again, it yielded strong cash generation in the quarter, which we use to fully pay down our revolving credit facility and return an additional $50 million of cash to shareholders via repurchases.
Fourth quarter Capital Markets fee revenue declined 15% from 2019, a market improvement from the 43% decline in the third quarter.
It is also worth noting that we decreased our loan loss credit reserves in the Americas by $9 million, partly offsetting the $31 million charge we took in the first quarter.
The sale and financing of the iconic Transamerica Pyramid Center in San Francisco for $650 million and $390 million respectively during the fourth quarter.
Looking at the global capital markets environment, investment sales dropped 21% in the quarter and 28% for the year according to JLL Research.
Consolidated leasing fee revenue declined 28% compared with the prior year quarter, a slight improvement from the 30% decline in the third quarter as clients continue to delay significant decisions regarding future real estate strategies.
Global office leasing volumes declined 43% in the fourth quarter compared with the 46% decline in the third quarter.
Our U.S. gross leasing pipeline has improved from mid-year lows and is up 5% year-over-year, though we emphasize closing rates and timing remain highly uncertain.
Our Corporate Solutions business fee revenue declined 7% in the quarter, a strong growth in Americas Facility Management was more than offset by ongoing headwinds in our project and development services and U.K. mobile engineering businesses.
Coming off a record $8 billion of capital raised in 2019, LaSalle raised $6.1 billion in 2020 demonstrating that capital continues to flow to investment managers with proven track records.
LaSalle's assets under management grew about $3 billion from the prior quarter to $69 billion.
For 2021, we anticipate around $25 million of incentive fees with very little in the first quarter.
Consistent with my statements on the third quarter call, we expect $135 million of annualized fixed cost savings from actions taken in 2020.
For the full year 2020, non-permanent cost savings totaled about $330 million, including about $85 million in the fourth quarter.
Major items that benefited our full-year profitability included approximately $250 million of cost mitigation savings in T&E, marketing and other expense areas and $80 million of government COVID relief programs.
Just under half of the $330 million of savings will not be repeated in 2021, as they represent finite actions, including government programs and temporary reductions to compensation and benefits.
Considering our cost saving initiatives, business mix and growth initiatives, we expect to operate within our 14% to 16% long-term adjusted EBITDA margin target range in 2021 and the years ahead.
The sequential improvement in earnings, our enhanced focus on improving asset efficiency and modest capex and investment spending allowed us to reduce net debt by $560 million in the quarter, which ended the year at $192 million.
At the end of December, reported leverage was 0.2 times, down from 0.8 times at the end of September and we had $3.3 billion of liquidity, including full availability of our $2.7 billion revolving credit facility.
As Christian mentioned, we are targeting reported net leverage ratio of 0.5 to 1.25 times over the long term, though there may be variances due to operational seasonality as well as timing of business reinvestment, M&A and share repurchases.
With the distribution of vaccines, the general sentiment supports a meaningful recovery in 2021, with some analysts forecasting global economic growth in excess of 5%, much of it coming in the second half of the year.

Summary:
Consolidated revenue fell 12% to $4.8 billion and fee revenue declined 19% to $2 billion in local currency.
Adjusted net income totaled $276 million for the quarter and adjusted diluted earnings per share totaled $5.29.
Our Corporate Solutions business fee revenue declined 7% in the quarter, a strong growth in Americas Facility Management was more than offset by ongoing headwinds in our project and development services and U.K. mobile engineering businesses.
Just under half of the $330 million of savings will not be repeated in 2021, as they represent finite actions, including government programs and temporary reductions to compensation and benefits.