As a reminder, I'll be referring to adjusted results today.
Fourth quarter revenues increased 5% sequentially to $498.5 million compared to our initial guidance range of $460 million to $485 million, and our revised guidance range of $494 million to $499 million.
During the fourth quarter, our channel partners further reduced the inventory levels by approximately $22 million as expected, resulting in a reduction of approximately $70 million for the full year 2020.
Incoming order rates were solid during the quarter, increasing 13% sequentially.
This resulted in a book-to-bill ratio of 1.10 times, including a robust 1.16 times in the Industrial Solutions segment.
EPS increased 25% sequentially to $0.90, compared to our initial guidance range of $0.63 to $0.78, and our revised guidance range of $0.85 to $0.90.
Free cash flow generation was $101 million in the quarter, which exceeded our expectations by approximately $11 million.
As a result, we exited the fourth quarter with cash on hand of $502 million, which provides ample flexibility as we pursue our strategic initiatives.
For the full year 2020, we delivered revenues of $1.863 billion and earnings per share of $2.75.
Free cash flow generation was $86 million compared to our expectation of approximately $75 million.
On the cost side, we delivered on our commitments by successfully reducing SG&A costs by $40 million for the full year 2020.
We exited the year with a quarterly run rate savings of $15 million in the fourth quarter, so we are prepared to deliver the full $60 million in savings in 2021 as planned.
This represents approximately 300 basis points of incremental EBITDA margin expansion on an annual basis.
To that end, R&D spending increased 14% to $107 million in 2020, with approximately 65% of this investment dedicated to software development.
We also maintained capex spending of approximately $70 million for the year, to ensure that we have the capabilities and capacity to fully participate in the anticipated growth in our key markets.
In addition, we initiated a process to divest approximately $200 million in revenues associated with certain undifferentiated copper cable product lines.
Finally, subsequent to the end of the fourth quarter, we announced the Bolton acquisition of OTN Systems for $71 million.
We expect the acquisition to contribute incremental revenue and earnings per share of approximately $36.11 million respectively during the 11 months of ownership in 2021.
After 20 years with Belden, the last nine as our CFO, Henk has announced his departure next month following a transition of duties to Jeremy parks.
Revenues were up $498.5 million in the quarter compared to $549.7 million in the fourth quarter of 2019.
Revenues decreased 9.3% on a year-over-year basis and increased 4.8% sequentially.
After adjusting for a $5.5 million favorable impact from acquisitions and a $14 million favorable impact on currency translation and higher copper prices, revenues declined 12.8% organically on a year-over-year basis.
After further adjusting for changes in channel inventory levels, revenues decreased 6.1% organically from the prior year.
On a sequential basis, revenues increased 2.9% organically after adjusting for a $9.1 million favorable impact from currency translation and higher copper prices.
After further adjusting for changes in channel inventory, revenues increased 9.6% organically on a sequential basis.
Incoming orders were solid during the quarter, increasing 13% sequentially.
This resulted in a book-to-bill ratio of 1.10 times [Phonetic] including robust 1.16 in the Industrial Solutions segment, and a 1.04 in the Enterprise Solutions segment.
Gross profit margins in the quarter were 35.4% consistent with the third quarter.
EBITDA was $74 million compared to $65.3 million in the prior quarter and $92.9 million in the prior year period.
EBITDA margins were 14.8% compared to 13.7% in the prior quarter and 16.9% in the prior year period.
As Roel mentioned, we successfully executed our SG&A cost reduction program by delivering savings of $15 million in the fourth quarter and $40 million for the full year.
We expect to deliver the full $60 million in savings in 2021.
We increased R&D investments by approximately 15% in the fourth quarter and the full year 2020.
At current foreign exchange rates, we expect interest expense to be approximately $61 million in 2021.
Our effective tax rate was 13.5% in the fourth quarter and 16.4% for the full year, as we benefited from incremental discrete tax planning initiatives.
For financial planning and modeling purposes, we recommend using an effective tax rate of 20% throughout 2021.
Net income in the quarter was $40.5 million compared to $32.2 million in the prior quarter and $54.9 million in the prior year period.
Earnings per share was $0.90 in the fourth quarter compared to $1.20 in the year-ago period.
Earnings per share increased 25% sequentially from $0.72 in the third quarter.
The Industrial Solutions segment generated revenues of $217.8 million in the quarter.
Currency translation and copper prices had a stable impact of $9.2 million year-over-year and $5.8 million sequentially.
After adjusting for these factors, revenues decreased 14% organically on a year-over-year basis and increased 7% sequentially.
After further adjusting for changes in channel inventory levels, revenues declined 8% year-over-year and increased 10% sequentially on an organic basis.
Within this segment, Industrial Automation revenues declined 8% year-over-year and increased 9% sequentially on an organic basis after adjusting for changes in channel inventory levels.
Cybersecurity revenues declined 14% in the fourth quarter on a year-over-year basis and increased 16% sequentially.
Notable bookings in the quarter included a Fortune 500 insurance company migrating from on-premise to-cloud based solutions, and a multinational financial services corporation expanding its coverage in preparation for expected future growth from acquisitions.
Nonrenewal bookings in this vertical increased 13% sequentially in the quarter and 31% for the full year.
SaaS offerings represented approximately 25% of nonrenewal bookings in the quarter compared to 10% a year-ago.
Industrial Solutions segment EBITDA margins were 17.5% in the quarter compared to 15.6% in the prior quarter and 20.1% in the year-ago period.
Our Enterprise Solutions segment generated revenues of $227.7 million during the quarter.
After adjusting for $5.5 million favorable impact from acquisitions and a $4.8 million favorable impact from currency translation and higher copper prices, revenues declined 12% organically on a year-over-year basis.
Revenues declined 2% sequentially after adjusting for a $3.3 million favorable impact from currency translation and higher copper prices.
After further adjusting for changes in channel and customer inventory levels, revenues declined 3% year-over-year and increased 9% sequentially on an organic basis.
Revenues in Broadband and 5G increased 8% year-over-year and 5% sequentially after adjusting for changes in customer inventory levels.
This supports continued robust growth in our fiber optics products, which increased 28% organically in 2020.
Revenues in Smart Buildings market declined 12% year-over-year and increased 13% sequentially on an organic basis after adjusting for changes in channel inventory.
Enterprise Solutions EBITDA margins were 11.5% in the quarter consistent with the prior quarter and compared to 13.7% in the prior year period.
Our cash and cash equivalents balance at the end of the fourth quarter was $502 million compared to $391 million in the prior quarter and $426 million in the prior year period.
Working capital turns was 10.3 turns compared to 6.6 turns in the prior quarter and 8.9 turns in the prior year period.
Days sales outstanding declined 8 days sequentially from 58 days in the prior quarter to 50 days.
Inventory turns was 5.2 turns compared to 5.0 turns in the prior quarter and 6.0 turns in the prior year.
Our total debt principal at the end of the fourth quarter was $1.59 billion compared to $1.52 billion in the third quarter.
Net leverage was 4.0 times net debt to EBITDA at the end of the quarter.
This is temporarily above our targeted range of 2 to 3 times and we expect to turn back to the targeted range as conditions normalize.
As a reminder, our debt is entirely fixed at an attractive average interest rate of 3.5%, with no maturities until 2025 to 2028.
Cash flow from operations in the fourth quarter was $134.7 million compared to $187.4 million in the prior year period.
Net capital expenditures were $33.3 million for the quarter compared to $35.9 million in the prior period.
For the full year 2020, we generated cash flow from operations of $173.4 million compared to $276.9 million in 2019.
The full year net capital expenditures were $87.1 million compared to $110 million in 2019.
As a result, we generated free cash flow of $86.3 million in 2020 compared to $166.9 million in 2019.
We anticipate first quarter 2021 revenues to be between $490 million and $505 million, and earnings per share of $0.60 to $0.70.
For the full year 2021, we expect revenues to be between $1.99 billion and $2.050 billion, and earnings per share of $2.90 to $3.30.
For financial modeling purposes, we recommend using interest expense of approximately $61 million for 2021, and then effective tax rate of 20% for each quarter and the full year.
It continues to include the contribution of our copper cable product lines that we are in the process of divesting, which contributed approximately $200 million in revenue and $0.20 in 0PS in 2020.
We expect current copper prices and foreign exchange rates to have a favorable impact on revenues of approximately $80 million in 2021, but a negligible impact on earnings.
We expect consolidated organic growth in the range of 1% to 4% or up to $70 million, with solid growth in our Industrial Solutions segment, partially offset by declines in the Smart Buildings markets within our Enterprise Solutions segment.
We anticipate an incremental $36 million in revenue and $0.11 in earnings per share from the OTN Systems acquisition.
Consistent with our commitment, we expect to realize the incremental $20 million in savings under our SG&A cost reduction program.
These savings represent $0.36 in EPS.
Finally, a normalized effective tax rate of 20% along with modestly higher interest expense and share count represent an earnings per share headwind of approximately $0.20 for the year.
For the full year 2021, the high-end of our guidance implies total revenue and earnings per share growth of 10% and 20% respectively.

Summary:
As a reminder, I'll be referring to adjusted results today.
EPS increased 25% sequentially to $0.90, compared to our initial guidance range of $0.63 to $0.78, and our revised guidance range of $0.85 to $0.90.
After 20 years with Belden, the last nine as our CFO, Henk has announced his departure next month following a transition of duties to Jeremy parks.
Revenues were up $498.5 million in the quarter compared to $549.7 million in the fourth quarter of 2019.
Earnings per share was $0.90 in the fourth quarter compared to $1.20 in the year-ago period.
We anticipate first quarter 2021 revenues to be between $490 million and $505 million, and earnings per share of $0.60 to $0.70.
For the full year 2021, we expect revenues to be between $1.99 billion and $2.050 billion, and earnings per share of $2.90 to $3.30.