Despite continued global economic uncertainly, demand for the Company's products and services remained strong.
New equipment sales increased largely due to increased sales of larger, higher value units. Mobile equipment sales to mining customers increased 50% year-over-year on significant deliveries from the order backlog. Revenues from power systems applications were 9% lower. Road construction was strong, although down 5% from records set last year. A broader product offering including new Caterpillar vocational truck and Sitech products increased revenues over $10 million.
Used equipment sales include sales of used equipment purchased for resale, equipment received on trade-in and sales of Company owned rental fleet. Used tractor equipment sales were lower year-over-year mainly due to reduced sales from the Company's rental fleet. Tractor used purchased sales were flat to prior year. Used equipment sales vary on factors such as product availability (both new and used), customer demands and the general pricing environment.
Rental revenues were higher on increased investment and improved utilization. The Company invested $55 million net of disposals in its rental fleet in 2012, compared to $35 million in the prior year. Utilization of both light and heavy equipment was good. Light equipment rentals increased 9% year-over-year while heavy equipment rental increased 28%. Equipment on rent with a purchase option increased 25%. Power rentals were 26% lower year-over-year. Generally, rental rates were fairly consistent in both years with continuing competitive market conditions. Same store sales were the significant contributor, with the new location in Bracebridge, Ontario, representing less than 10% the year-over-year increase.
Power generation revenues from Toromont-owned plants were lower, largely reflecting decreased operating hours at the Waterloo facility due to a reduced availability of landfill gas.
Product support revenues were a record in 2012, 16% higher than the previous record set in 2011. Product support revenues in 2012 benefited from an increased installed base of equipment in our territory coupled with higher utilization of equipment. Most markets have seen higher product support activity year-over-year. The Equipment Group added a net 88 technicians in 2012. Both service and parts revenues set new records in 2012.
Operating income was up, in part reflecting the 9% increase in revenues. Gross margin as a percentage of revenues increased 40 basis points compared to 2011 on sales mix, with a larger proportion of product support revenues to total in the current year. Equipment gross margin was lower in the year on competitive market conditions, offset by improved product support gross margins. Selling and administrative expenses increased 7% on the 9% increase in revenues. Higher costs were reported across a number of areas including compensation, freight, training and occupancy. Operating income as a percentage of revenues was 11.9% in 2012 versus 11.2% in 2011.
Capital expenditures in the Equipment Group totalled $99.9 million in 2012. Replacement and expansion of the rental fleet accounted for $77.6 million of total investment in 2012. Expenditures of $3.7 million related to new and expanded facilities to meet current and future growth requirements. Other capital expenditures included $13.8 million on service and delivery vehicles.
Toromont secured the coterminous Buycrus distribution network from Caterpillar for $13.7 million. The addition of the former Bucyrus products, now rebranded CAT, strengthens Toromont's mining offering with a much broader product line addressing surface and underground mining requirements. Total revenues associated with former Bucyrus products totalled $24.6 million for the year, of which $8.8 million was recognized after the acquisition.
($ millions) 2012 2011 $ change % change----------------------------------------------------------------------------Bookings - year ended December 31 $ 614 $ 635 $ (21) (3%)Backlogs - as at December 31 $ 128 $ 224 $ (96) (43%)