experienced lower wages and benefits expense in the fourth quarter of 2021 versus the prior year due largely to reduced incentive compensation incurred in the fourth quarter of 2021. Lower SG&A expenses in the fourth quarter of 2021 were partly mitigated by higher severance costs during the fourth quarter of 2021 driven by rightsizing activities. Lastly, lower operating expenses included reduced research, development and engineering expenses of $1.6 million, or 25%, from last year primarily as a result of lower project activity, coupled with lower wages and benefits driven by reduced headcount.
Net loss in the fourth quarter of 2021 was $7.6 million, or a loss of $0.33 per share, versus a net loss of $3.1 million, or $0.13 per share for the comparable prior year period. Adjusted net loss was $5.7 million, or Adjusted loss per share of $0.25, versus Adjusted net income of $1.1 million, or Adjusted earnings per share of $0.05 for the fourth quarter of 2020. Adjusted earnings before interest, taxes, depreciation and amortization (“EBITDA”) was a loss of $1.9 million compared to Adjusted EBITDA of $4.7 million in the fourth quarter last year.
See “Non-GAAP Financial Measures” below for the Company’s definition of total Adjusted net income (loss), Adjusted earnings (loss) per share, EBITDA and Adjusted EBITDA and the financial tables that accompany this release for reconciliations of these measures to their closest comparable GAAP measures.
Debt and Liquidity
The Company’s total debt was approximately $181 million at December 31, 2021, while cash and cash equivalents were approximately $6 million. This compares to total debt of approximately $156 million and cash and cash equivalents of approximately $5 million at September 30, 2021. Included in the Company’s total debt at December 31, 2021 were borrowings of $130 million under the Uncommitted Revolving Credit Agreement with Standard Chartered Bank (the “Credit Agreement”), and borrowings of $25 million and $25 million under the Second and Third Shareholder’s Loan Agreements with Weichai America Corp. (“Weichai”), its majority stockholder, respectively. The Credit Agreement included financial covenants which were effective for the Company during the three months ended December 31, 2021, including an interest coverage ratio and a minimum EBITDA threshold, as further defined in the Credit Agreement. For the three months ended December 31, 2021, the Company did not meet these covenants. On March 25, 2022, in connection with the extension of the Credit Agreement, the Company entered into a waiver with Standard Chartered, which waived the financial covenant defaults for the quarter ended December 31, 2021. No additional fee was incurred with this waiver.
On March 25, 2022, PSI entered into an amended $130.0 million Credit Agreement (the “Second Amended and Restated Credit Agreement”) with Standard Chartered Bank, which among other items, extends the maturity date of loans outstanding under the Company’s previous Credit Agreement to the earlier of March 24, 2023 or the demand of Standard Chartered. In connection with the Second Amended and Restated Credit Agreement, on March 25, 2022, the Company also amended two of its three separate shareholder’s loan agreements with its majority stockholder, Weichai America Corp. (“Weichai”), to among other things, extend the maturities thereof. Additional details are available in the Company’s Form 8-K filed on March 28, 2022.
Outlook for 2022
The Company expects its sales in 2022 to increase by at least 3% versus 2021 levels, a result of expectations for strong growth in the industrial and power systems end markets, partly mitigated by a reduction in sales in the transportation end market. Gross profit as a percentage of sales is targeted to improve by at least 5 percentage points in 2022, a function of lower warranty expense, pricing actions, improved cost recovery and cost savings initiatives. Notwithstanding this outlook, which is being driven in part by expectations for an improvement in supply chain dynamics, including timelier availability of parts, and a continuation of favorable economic conditions within the United States and across the Company’s various markets, the Company cautions that significant uncertainty remains as a result of supply chain challenges, inflationary costs, commodity volatility, and the COVID-19 pandemic, among other factors.