AGL Resources's second-quarter profits soared 89 percent to $34 million, or 28 cents a share, the company said early Wednesday.

Atlanta-based AGL, the nation's largest natural gas-only distribution company, had a net income of $18 million, or 23 cents a share for the same period a year ago.

Earnings for the company's utilities, which includes Atlanta Gas Light, was $100 million, compared with $74 million during the same time a year ago. AGL's purchase of Illinois-based Nicor Gas helped contribute to the increase, the company said.

AGL bought Nicor Gas in a deal that closed last December.

AGL warned that its year-end earnings may be lower than the projected $2.80 to $2.95 cents a share. A warm start to 2012 is the main factor, the company said.