Avista Corp. reported lower third-quarter earnings of $10.7 million, or 18 cents per share, compared with $12.3 million, or 22 cents per share, for the third quarter of 2010. The results, released Wednesday, were in line with the Spokane-based utility’s expectations, said Scott Morris, Avista’s chairman and chief executive officer. The company reported robust earnings through the first nine months of the year. Avista’s income was $75.6 million, or $1.30 per share, through Sept. 30, compared with $66.7 million, or $1.20 per share, for the same period in 2010.