Enphase Energy, the Petaluma-based solar components manufacturer that went public in March with a $54 million stock offering, saw revenues grow 88 percent in its second quarter compared to the same time last year, company officials said Tuesday.

Net sales stood at $55.7 million in the quarter that ended June 30, compared to $29.6 million in the second quarter of 2011.

The company's microinverter technology boosts the output of solar energy systems.

"We're very proud of the quarter," said Paul Nahi, CEO of Enphase Energy. "Our momentum continued in our second quarter as we lead the solar industry in the transition to microinverters."

The company also has been expanding its presence in Europe, where interest in its products is strog, Nahi said in a conference call with shareholders.

"The traction in Europe has been outstanding," Nahi said.

Enphase employs about 400 people worldwide, with about 300 in Petaluma, Nahi said. Overall staffing grew by 80 people across engineering, sales, marketing and other categories, he said.

The company hired additional staff for research and development, and made progress on its hiring goals in the second quarter, said Sanjeev Kumar, chief financial officer.

But the company lost $11.4 million, or 29 cents a share, in the quarter. The company chose to invest in growth because it has a leadership position with microinverters, Nahi said.

"We are very mindful of our goal of profitability," Kumar said.

"As a young company, we constantly have to make the decision as to whether we want to invest in growth ... or do we want to pull back and not expand as rapidly," Nahi said.

Enphase expects net revenues for the third quarter of 2012 to range from $59 million to $63 million, officials said. Shares of Enphase stock closed at $6.67 on the Nasdaq exchange, up 5 percent from Tuesday's close.

The company also announced that Kumar would be leaving the company later this year.

"It was not an easy decision to make," Kumar said. "I'm very committed to a smooth transition to a new CFO."