Standard & Poor's downgrading of Greece's long-term ratings to 'selective default' could well be short but there is a risk Athens falls back into default later, S&P analyst Moritz Kraemer said on Tuesday.

S&P cut Greece's rating on Monday, the second ratings agency to proceed with a widely expected downgrade after Athens announced a bond swap plan to lighten its debt burden.

It's a distinct possibility that this will be a short default which will be cured, Kraemer told Reuters Insider television. The more interesting question is not when it will be cured but whether it will be the last one.

I think the rating coming out of default of the Hellenic Republic will give some indication of what the likelihood of another restructuring down the road would be.

When assessing what rating to give Greece in the future, S&P would look at the political environment, the growth outlook and the remaining debt stock.

We think that on all three fronts there are huge question marks, said Kraemer.

(Reporting by Axel Threlfall, writing by Paul Carrel)