Speaking as part of a Q&A, the publisher said:
Don't count out the possibility of a new game in the L.A. Noire franchise in the future. We simply have not decided anything. We're all very pleased with how that game turned out and are considering what the future may hold for L.A. Noire as a series.
However, Rockstar was keen to point out that it’s in no rush to get to work on a sequel:
We don't always rush to make sequels, but that does not mean we won't get to them eventually - see Max and Red Dead for evidence of that - we have so many games we want to make and the issue is always one of bandwidth and timing.
Switching the subject to Grand Theft Auto V, the publisher teased that we can expect more details on the mega sequel in the coming months:
We know that there are a ton of questions you all have about [Grand Theft Auto V], including release date and lots else.
Right now, we are very hard at work on the game and are excited as well to show and tell you more as development progresses - expect that we'll be talking much more about GTAV starting at some point in a few months' time.
We’ll see you right around E3.