The company earned $2.18 billion US, or $6.53 per share, during the three months ending in September. That compared with net income of $2.73 billion, or $8.33 per share, last year.
The results were well below what analysts polled by Thomson Reuters were expecting.
But the bigger story is the timing of the release Thursday.
Google typically releases results after stock markets have closed, so investors were expecting the data to come after 4 p.m. ET.
But early in the afternoon, Google posted its results, which sent the stock into a tailspin. The shares lost $68, or more than nine per cent, to trade at $687.30 on the Nasdaq. The sell-off has knocked more than $19 billion off the value of the company.
At the company's request, the stock exchange halted trading in the shares a little before 1 p.m. eastern time.
The release included the curious line "PENDING LARRY QUOTE" in the second line — suggesting that spot was reserved for a boilerplate quote from CEO Larry Page, and someone had perhaps posted the release inadvertently.
At 1:30 p.m., Google issued a statement that supports that theory, saying the company's financial printer, R. R. Donnelley, "filed our draft 8K earnings statement without authorization."
"Once it's finalized, we will release our earnings, resume trading on Nasdaq," Google said.