We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range $100-450$ solar masses and with the component mass ratios between $1:1$ and $4:1$. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on $88+88$ solar masses, for non-spinning sources, the rate density upper limit is 0.13 per $\text{Mpc}^3$ per Myr at the 90% confidence level.