Selling, general and administrative (SG&A) expenses decreased to $43.0 million in Q4 FY2013 from $44.7 million in Q4 FY2012, reflecting the minimum $3.7 million liability accrued in Q4 FY2012 related to the investigation into the Foreign Corrupt Practices Act, which has not changed, and reductions in short and long term incentive compensation of $4.1 million, offset by costs of $1.4 million associated with newly acquired operations, $0.5 million of higher legal and professional fees, and $5.1 million related to executive transition and other costs associated with the relocation of our corporate headquarters.
Depreciation and amortization increased to $16.9 million from $16.0 million last year, due to assets acquired through the purchase of Diberil in Q2 FY2013, and increases associated with other equipment additions. The increases were partially offset by lower amortization expense of intangible assets from prior acquisitions, which became fully amortized earlier in FY2013.
Equity in earnings of affiliates decreased to $1.5 million from $5.6 million, primarily due to a decline in earnings from our South American affiliates in Mineral Exploration, whose results were impacted by similar slowdowns in exploration activity as experienced in our wholly owned operations.
Interest expense increased to $1.3 million from $0.6 million, due primarily to higher borrowing on our revolving credit facilities to fund capital expenditures, acquisitions and working capital needs.Other income, net, of $1.7 million consisted primarily of gains on sales of surplus equipment. Income tax benefits for continuing operations of $14.4 million (an effective rate of 39.5%) and $11.7 million (an effective rate of 12.0%) were recorded for Q4 FY2013 and Q4 FY2012. The majority of the impairment charges recorded in Q4 FY2012 were not tax deductible and had no income tax benefit recognized for them. FY 2013 Overview Revenues of $1.1 billion were substantially unchanged in total from FY2012, with decreases in Heavy Civil and Mineral Exploration offset by revenue from an acquisition and other increases in Geoconstruction.