CONCORD, N.H. (AP) — Nearly a decade after it was first brought, a lawsuit accusing two oil giants of widespread groundwater contamination in New Hampshire is expected to present jurors with the most complex and time-consuming trial in state history.

The products liability case against ExxonMobil and Citgo will be tried beginning in mid-January in a federal courtroom — on loan to the state — because it would undermine the rights of criminal defendants to a speedy trial if it tied up one of the three courtrooms in Merrimack Superior Court, officials said.