Correction: An earlier version of the story incorrectly stated that SunPower's marketing chief had been laid off.

SunPower Corp. isn't immune to a growing industry trend: layoffs.

Thesolarpanel maker in San Jose, Calif. confirmed to Greentech Media it had let about 60 people go, or 1.2 percent of its 5,000-person workforce, said Stephen Wright, the company's director of corporate communications Thursday. The company declined to say more until after it discusses its quarterly earnings in the afternoon.

A source told Greentech Media that Whitney Thomlin, a manager at SunPower's installation business, and Stephen Kelley, a sales director, were laid off. 

SunPower's Class A shares declined nearly 6 percent to reach $28.66 per share in recent trading. Its Class B shares were down about 7 percent to reach $21.81 per share.

Layoffs have become a norm in the solar business. Just this week, Palo Alto, Calif.-based Ausra confirmed it had shed 10 percent of its staff after Greentech Media first reported the layoffs. Not only that, the company is changing its business model (see Ausra Update: Layoffs Confirmed and a Change of Business Plans).

Greentech Media also first reported that OptiSolar has slashed about 50 percent of its staff. Suntech Power Holdings has cut 10 percent of its staff while running its factories at 50 percent to 60 percent capacity. HelioVolt and SunEdison also have shrunk their work forces (see Greenlight post).

SunPower is scheduled to discuss its quarterly earnings this afternoon.

The economic downturn has made it difficult to forecast market demands, which in turn has prompted solar companies and their customers to cut backs or slow any expansion plans.

That cautious approach could hurt SunPower more than some of its competitors because the company has branded itself as a maker of premium solar panels, equity analysts said.

The company's pricier equipment could become less attractive at a time when its customers or potential customers are tightening their spending, said Gordon Johnson, head of alternative energy research at Hapoalim Securities in a research note Thursday.

"We believe SunPower's luxury brand will prove to be its 'Achilles Heel' in an oversupplied solar market," Johnson wrote.

SunPower uses monocrystalline silicon, which is more expensive than multicrystalline silicon but yields better performance in converting sunlight into electricity.