Mild summer weather, the recession and the absence of one-time gains led to a decline in third-quarter net income for Hartford-based Northeast Utilities, the company said Monday.

NU earned a net $64.8 million, or 37 cents a share, in the three months ended Sept. 30. That was down from $72.7 million, or 47 cents a share in the 2008 third quarter.

Charles Shivery, the NU chairman and chief executive officer, said he was satisfied with the performance, and that the decline was anticipated. But he said the results bolster arguments for higher electric rates.

Sales of electricity in the Connecticut Light & Power business were down 5 percent, most of which was attributable to milder weather, the company said.

Earnings from distribution and generation totaled $22.5 million, down from $35.5 million, as Connecticut Light & Power fell by more than half, to $11.4 million. Yankee Gas, whose profits are part of the distribution business, saw a 5.8 percent increase in natural gas sales, but reported a net loss of $4.5 million for the quarter due to uncollected bills, compared with a $2.3 million loss one year earlier.

Transmission earnings were $42.8 million, up from $35.9 million. NU's non-regulated competitive businesses earned $300,000, down from $4.6 million.

"Our electric distribution segment has been the part of our company most impacted by the economy and volatile financial markets, which have caused sales declines and rising uncollectable receivable balances and pension expense," Shivery said. "While strong cost management efforts have offset some of the impact of the economy, rate relief is pivotal to maintaining the financial health of this segment, which builds and maintains critical energy delivery infrastructure and [is] central to implementing many of the region's energy policies."