Reparations and Property rights

When an individuals rights are infringed, that individual has the right to seek and receive reparations from the assailant. The assailant may be an individual or a firm. But what happens when the assailant firm A has yet to absolve itself, and is purchased by another firm B? The onus then transfers to then transfers to firm B.

Is there a libertarian law term for this? Which author should I look more into to understand this quandry?

Robert Nozick (a minarchist and more of a philosopher than an economist) talks about justice of transfer and entitlement theory. http://en.wikipedia.org/wiki/Robert_Nozick