The battle between Vectren Corporation and developers of the coal-to-gas plant proposed to be built at Rockport continued in the state Senate Monday as a senator took aim at Vectren’s coal purchases.

The chamber was debating a bill that could trigger another round of regulatory reviews of the state’s 30-year contract to buy and then resell the synthetic natural gas produced at the plant being financed by Leucadia National Corporation.

Sen. Lindel Hume of Princeton, offered an amendment that was a shot at Vectren, which has opposed that Rockport plant.

His proposal would have required utilities such as Vectren that purchase coal from their own subsidiaries to pay the average market price for that coal, rather than higher prices they’ve negotiated for themselves.

Hume said they cannot gouge the consumer and that they can simply pass along the going rate for coal if they bought it on the open market.

His proposal was ultimately voted down as senators decided it had little to do with the overall bill.