UPDATE 2-SunPower profit tops Wall St, outlook disappoints

* Q3 EPS 42 cents vs Street view of 40 cents per share

* Q3 revenue of $466 mln vs $378 mln a year ago

* Full-year EPS forecast trimmed to lower end of range

* Shares down 13 pct at $29.25 after hours (Adds forecast, executive comment)

LOS ANGELES, Oct 22 (Reuters) - SunPower Corp posted better-than-expected quarterly profit but trimmed its full-year earnings forecast to the low end of its previous range, sending its shares down 13 percent.

Net profit for the third quarter ended Sept. 27 fell to $12.8 million, or 13 cents per share, from $24 million, or 29 cents per share, a year ago.

Excluding amortization of non-tangible assets, stock-based compensation and non-cash interest expense, SunPower's earnings per share of 42 cents beat analysts' forecast for 40 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 24 percent to $466 million and topped analysts' expectations for $420 million.

SunPower said it now expected full-year net income to be between $1.15 to $1.25 per share, the lower end of its previous range of $1.15 to $1.60 per share.

It said revenue for year would range between $1.425 billion and $1.50 billion, compared with its July forecast for $1.35 billion to $1.7 billion.

Like other makers of photovoltaic solar modules that turn sunlight into electricity, SunPower has seen demand for its products decline in the past year as the global credit crisis choked off financing for new projects.

The company said that environment was beginning to turn around.

"Although the financing markets remain challenging, we're starting to see some improvement in the availability of financing for our projects," SunPower Chief Financial Officer Dennis Arriola said in a statement.

Shares of SunPower fell 13 percent to $29.05 after hours after closing at $33.30 on the Nasdaq. (Reporting by Laura Isensee and Matt Daily in New York; Editing by Richard Chang)