  We present first results of our on-going BIMA Key Project: imaging the
CO(1-0) emission from a sample of 10 luminous IR galaxies (LIRGs) that are at
various merging stages, with special emphasis on systems apparently in the
early/intermediate stages of merging. We present here CO images with $\sim 5''$
resolution. An important result is the recognition of a plausible pre-starburst
phase in some early LIRG mergers (e.g., Arp 302 and NGC 6670). Our initial
analysis suggests that a merger-induced starburst phase may not begin before
the nuclear separation between the merging galaxies reaches roughly 10 kpc. The
surface gas density seems to increase from a few times $10^2 \Msun pc^{-2} to
>10^3 \Msun pc^{-2}$ while the prominent CO extent systematically decreases as
merging progresses.
