Amazon.com Inc posted a quarterly net profit on Thursday that fell by 10 percent as foreign currency fluctuations and a legal settlement hit earnings at the world's largest online retailer, sending shares down more than 5 percent.

Amazon, fresh from announcing on Wednesday it would acquire online shoe store Zappos.com for some $928 million, said net profit in the second quarter fell 10 percent to $142 million, or 32 cents per share, from $158 million, or 37 cents per share, a year earlier.

Operating profit was $159 million, a 27 percent drop, caused by changes in foreign exchange rates and a settlement with Toysrus.com.

Revenue rose 14 percent to $4.65 billion -- shy of the $4.69 billion analyst estimate. Excluding currency fluctuations, revenue rose 20 percent.

Amazon had forecast second-quarter revenue of $4.3 billion to $4.75 billion and an operating profit of $110 million to $190 million.

Looking ahead, Amazon forecast third-quarter revenue of $4.75 billion to $5.25 billion -- compared with the $4.92 billion expected by analysts -- with operating profit between $120 million and $210 million.

Shares fell 5.6 percent to $88.62 after closing on the Nasdaq at $93.87, up 5.7 percent.

(Reporting by Alexandria Sage; Editing by Steve Orlofsky)

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