Ameren Corp. will try again later this month to win regulatory approval in Missouri for a 100-mile (160km) segment of its 345kV Mark Twain transmission line, which would bring low-cost wind energy to there and Illinois from Iowa.

The 480-mile project has suffered from years of legal and regulatory delays in Missouri, whose key central location makes it the most direct pathway between Iowa and some load centres located along or east of the Mississippi River.