NetSuite added to its online CRM and accounting applications today by acquiring OpenAir for $26 million, including the assumption of $5 million of restricted stock that will continue to vest through 2010. Boston-based OpenAir sells Web-based software aimed at professional services firms, including timesheets, expense reports and project management.

The acquisition isn’t a huge win for investors Fidelity Capital, 3i, i-Hatch Ventures, and Rex Capital, who have already sunk $16 million into the company. The deal was all cash, net of the cash on OpenAir’s books and the $5 million in restricted stock. NetSuite will keep all 56 employees.

If NetSuite can do a better job pushing OpenAir’s Web-based software to its larger base of existing customers and reach new professional service customers as well, the acquisition will look like a deal.