There's a couple rumors posted on Finnish newsmedia per the Friends of Formula 1 Austin guys. Here's one of the sites they linked as a source. I can't find squat on this in English, though, so take it with a grain of salt. "Financial difficulties" are the rumored reason.

I can't imagine many Finns would be all that happy with Lotus right now after not paying Kimi, so there's that, too. Is anyone seeing anything more on this?

This would suck for Grosjean. Maldonado...ehhhhh, I'm less concerned with him. Heh.