  We investigate the possible commensurabilities to be expected when two
protoplanets in the Jovian mass range, gravitationally interacting with each
other and an external protoplanetary disc, are driven by disc induced orbital
migration of the outer protoplanet into a commensurability which is then
maintained in subsequent evolution. We find that for a variety of protoplanet
masses and typical protoplanetary disc properties, as well as the setting up of
2:1 commensurabilities of the type recently observed in GJ876, 3:1
commensurabilities are often formed, in addition to 4:1, 5:1, and 5:2
commensurabilities which occur less frequently. The higher order
commensurabilites are favoured when either one of the planets is massive, or
the inner planet begins with a significant orbital eccentricity. Detection of
such commensurabilities could yield important information relating to the
operation of protoplanet disc interactions during and shortly post formation.
