The Iowa Utilities Board gave conditional approval Thursday to an energy rate agreement with the state’s largest energy company. Utilities Board spokesman Chuck Seele says the Board approved the agreement with MidAmerican Energy.He says the settlement would freeze the company’s electricity rates through the year 2005. The deal also lets the company put any electric profits into the cost of constructing new electric plants. Seele says the original deal would’ve required the company to refund the profits to customers if they didn’t use them by 2005 to build new plants.The Board modified that provision to allow for an annual review of the company’s profits, so they can be returned quickly if there’s and excess. Seele says another modification approved Thursday would allow the company to balance out rates by raising low rates with a corresponding decrease in service areas with higher rates.Seele says the settlement must still be approved by union electrical workers and John Deere. Those groups have ten days to respond to the proposal.