The Greater Boston office market absorbed roughly 50,000 square feet of space in the last year, the first positive year-over-year absorption since early 2009, according to Lincoln Property Co (LPC).

The vacancy rate for the entire Greater Boston market dipped to an even 15 percent from the fourth quarter of 2011’s rate of 15.3 percent.

In the first quarter of 2012, the Class A office market in Boston’s Financial District measured the largest improvement, with more than 336,000 square feet of positive absorption. But despite that good news, the Financial District’s 15.3 percent vacancy rate remains the highest in the downtown market, according to LPC.

Overall, the average asking rent for the Greater Boston office market increased by approximately 75 cents in the first quarter to $27.41 per square foot. Average rents in Boston rose to $41.41 a square foot, and in Cambridge to $43.52, influencing the overall rate’s rise the most. A slight increase in Interstate-495 average rents to $17.07 was unexpected.

At the conclusion of 2011, the overall vacancy rate for the Boston market peaked at 12.2 percent. But the first quarter of 2012 dropped that rate to 11.7 percent, with the Class A market dropping to 11.4 percent vacant. Both the sublease rate and availability rate also declined, but the drop in vacancy was by far the most significant, LPC reports. With the decrease in all the above rates, the average asking rate for the Boston office market increased in both the Class A and B markets.

The overall rate measured $41.41 per square foot at the end of the first quarter, resulting in a quarter increase of 4.6 percent. The Back Bay overall average asking rate was the highest in the first quarter with an overall average of $44.81 per square foot. But in the Class A market, the Financial District measured a 5.6 percent increase in the first quarter for the highest average asking rate of $49.01 per square foot, according to LPC.