If you reduce the number of litigation firms you use, you can either transition cases or run out the string

Law departments that converge – significantly shrink the number of law firms used – can take pending cases away from the firms that don’t make the short list or they can bar in-house counsel from giving them more. The former raises transition fears; the latter stretches out the payoff of convergence and may increase fees. Some law departments have engineered wholesale transfers of cases to the new firms. If you let firms handle cases to conclusion even while they know they will get no more work from you, it would not surprise anyone that bills might increase. You certainly can’t kick off the better rates, discounts, or other benefits offered by the new panel firms.

Of course, where a non-panel firm handles a number of cases, a general counsel can decide on a mix of the two choices. I lean toward transferring cases to the new firms, all but those on the eve of trial, and obliging the new firm to cap the investment they will make in coming up to speed.