Nov 6 (Reuters) - Utility firm Ameren Corp AEE.N posted a fall in third-quarter profit on Wednesday, hurt by higher operating costs and lower sales due to a dip in heating demand.

Utilities grappled with higher costs, propelled by interest rates which were at elevated levels for much of the reported quarter.

The company's interest expenses rose 13.8% to $173 million, while operating expenses rose 8.9% to $1.59 billion.

The company also noted lower Ameren Missouri electric retail sales driven by milder summer temperatures, compared to the year-ago period, which weighed on earnings.

A 2.8% fall in electric retail sales in all its segments offset a 5.5% gain in revenues, which came up to $2.17 billion, nearly matching analysts' estimates as per LSEG data.

Ameren, which serves 2.4 million electric customers and more than 900,000 natural gas customers, said it expects 2025 earnings per share between $4.85 and $5.05 per share, the mid-point of which is slightly above estimates of $4.92 per share.

The company said its adjusted profit came in $1.87 per share, for the quarter ended Sept. 30, falling short of estimates of $1.91 per share.

(Reporting by Seher Dareen and Sourasis Bose in Bengaluru; Editing by Maju Samuel)

((Sourasis.Bose@thomsonreuters.com;))