Cemtrex Inc., a Farmingdale manufacturing services company, reported Monday that third-quarter revenue climbed, but higher general and administrative costs led to thinner margins and a decline in net profit.

Revenue for the three-month period ended June 30 increased 13 percent to $27.8 million, compared with the 2016 period.

advertisement | advertise on newsday

But operating margins fell to 5.1 percent from 6.9 percent in the year-earlier quarter. Cemtrex attributed the lower margins to “an increase in operating expenses of 31 percent to $8.5 million . . . which includes an increase of sales, marketing and professional service costs.”

That led net income to decline to $1.2 million, or 11 cents per diluted share, from $1.4 million, or 16 cents per diluted share, in the previous year’s quarter.

“In April 2017, we received a record number of new incoming orders for a single month, totaling over $21 million,” Saagar Govil, chief executive and chairman of Cemtrex, said in a statement. “Included in these orders is a $15 million, three year agreement with one of our existing customers, which is the single largest order we have ever received.”

Shares of Cemtrex fell 6.7 percent to close at $3.22 on Monday. The company’s stock price has fallen about 43 percent in the past 12 months.

advertisement | advertise on newsday

Cemtrex manufactures custom electronics and instruments for monitoring and controlling pollutants and greenhouse gases.