Capstone Turbine Corp. trimmed its net loss during the fiscal first quarter and beat Wall Street estimates for revenue, the company announced Thursday. The Chatsworth alternative energy company reported a net loss of $6 million (-2 cents a share) for the quarter ending June 30, compared with a net loss of $6.7 million (-2 cents) in the same period a year earlier. Revenue jumped 16 percent to $27 million. Analysts on average expected a loss of 2 cents on revenue of $25.4 million, according to Thomson Financial Network. Capstone Chief Executive Darren Jamison attributed the performance to strong sales in the aftermarket as well as improvements in sales to oil and gas customers. “Our geographical diversification is also paying off, as we are making good progress in developing our markets in Mexico, South America, Africa and the Middle East,” Jamison said in a prepared statement. Capstone is adding up to 100 salespeople by the end of the year and beefing up its marketing campaign to capture additional market opportunities, he added. Shares closed down 1 cent, or more than 2 percent, to 31 cents on the Nasdaq.