The sale price of office properties in Greater Boston that are 90 percent to 100 percent leased are hitting a five-year high mark this year, according to the Boston office of commercial real estate firm Lincoln Property Co.

Year-to-date sales volume has also surpassed the total sales volume from last year, according to a statement.

"Even with these positive signs, however, there is of 3.8 percent drop in the average price-per-square-foot mark when compared to 2009’s average," said Scott Faber, director of research at Lincoln Property Co. "Although sales of well-leased assets have climbed above previous peaks seen in 2006-2008, these assets typically include long-term leases to single tenants who have excellent credit and are in stable industries such as education, health care and pharmaceutical. Office assets that don’t meet this criteria or have large tenant roll-overs in the next two to three years are not likely to obtain optimal price due to stringent underwriting for years 2010-2012."

The gap in the value of leased and vacant properties has also widened, according to a statement. An average price-per-square-foot for a relatively vacant office property in Greater Boston today stands at $141.88, as compared with $241.74, for properties that are 90 percent to 100 percent leased.

"Current transactions certainly have produced mixed signals especially when you consider the product that has been on the market, but then pulled in 2010," said Sean Chrisom, senior vice president of investments at Lincoln Property Co. "However, the most important signal is that interest and capital is out there and ready to move – but, just for the right price."