We are reporting organic service revenue growth across all of our service offerings. On a sequential basis, while total revenue was relatively consistent with the fourth quarter of 2010. There was a shift in the underlying mix of the revenue. Service revenue increased by $2 million or 11.5% while softer revenue decreased by $2.1 million. The sequential increase in service revenue is primarily driven by sequential increases in our EPM and the RP related service offerings.
Software revenue which includes maintenance revenue representing 6.7% of our total revenue during the first quarter, this compared to 14.4% during the first quarter 2010. On an absolute dollar basis software revenue decreased by $1.3 million on a year over year basis, which is in large part driven by a singular software sale during the first quarter 2010. As we have stated in each of our past earnings calls, we’d like to remind everyone that we anticipate that software revenue will be a material part of future total revenue and hat our future operating results can be materially influenced by our ability to recognize software.
Also we’d like to reemphasize that quarterly software revenue can be volatile if subject to our customers demand for such off the shelf third party software. It can be impacted by software based revenue recognition rules. Quickly touching upon some of our other first quarter revenue metrics before moving on to gross profits, our annualized service revenue per billable consultant metric was $327,000 in the first quarter of 2011, which is consistent with the first quarter 2010.
We entered into first time engagements with 31 new customers during the quarter compared to 25 new customers in the year ago quarter. Service revenue generated by our top ten customers represented 25.9% of total revenue service compared to 30.3% in the first quarter of 2010. Only one individual customer accounts for more than 5% of our total service revenue during the current quarter.