SIOUX FALLS, S.D. (AP) – A next-generation biofuels company says it’s suspending plans to produce isobutanol from corn at its Minnesota plant and will instead make ethanol in the near term while it tweaks its process. Isobutanol is an industrial chemical that can be used as an additive to gasoline, plastics and paints. Englewood, Colo.-based Gevo Inc. had hoped that its Luverne, Minn., plant would be producing 1 million gallons of isobutanol per month by the end of the year. Its CEO now says that will likely happen sometime in 2013. The pushed-back timetable could also delay the conversion of a Redfield, co-op corn ethanol plant into a biobutanol plant to sometime in 2014. Gevo made the announcement late Monday. On Tuesday, its shares plunged 35 percent to $2.14 per share.