Google Shares fell $40 a share after hours as it reported per-share earnings that missed Wall Street expectations.

CEO Eric Schmidt acknowledged the economic climate is “challenging.”

The Mountain View, Calif., company reported revenue, excluding commissions paid to marketing partners that were in line with Wall Street estimates, as income rose 35%,  as its, but its per- share earnings missed the consensus Wall Street estimate by 11 cents.

Google shares fell as low as $470.55 in late trading, wiping away $15 billion in market value.

Over the past 52 weeks, the stock has traded between $412.11 and $747.24.

For the quarter ended June 30, Google reported net income of $1.25 billion, or $3.92 a share, up from $925.1 million, or $2.93 a share, a year earlier. Net income fell from $1.31 billion, or $4.12 a share, in the first quarter.

Excluding stock-option costs, per-share earnings were $4.63, below the average analyst estimate of $4.74, according to Thomson Reuters.

Revenue jumped 39% from a year earlier to $5.37 billion. Excluding traffic- acquisition costs of $1.47 billion, the company’s revenue was $3.9 billion, slightly above the Thomson Reuters estimate of $3.87 billion.

Google’s U.S. paid clicks for the second quarter rose 19% from a year earlier, surpassing Citigroup’s estimate for 16% growth.

Google’s U.S. paid clicks for the first quarter grew 20% over the year ago period, a sharp deceleration from the company’s 30% growth rate in fourth quarter and 45% growth in the third quarter.

Microsoft also missed its earning expectations and their stock was down 6% in aftermarket trading.