CENTERVILLE -- Vectren natural gas residential customers in seven south suburban communities should be able to save $45 to $55 annually, and small businesses in the same communities, from $200 to $250 annually, with a switch from Vectren to IGS Energy (Interstate Gas Supply) through an optout natural gas aggregation program.

The agreement is for residential and small commercial customers that use less than 5,000 ccfs of gas a year.