(Adds details on spending, ad revenue, background, share price)
Feb 1 (Reuters) - Alphabet Inc's fourth-quarter profit fell short of Wall Street forecasts as Google's parent company invested heavily on self-driving cars, smartphones and home devices, while its core internet advertising business remained strong.
Shares of the company fell 2.7 percent to $1,137 in after-hours trading on Thursday.
Alphabet posted a net loss of $3.02 billion or $4.35 per Class A and B share and Class C capital stock in the quarter ended Dec. 31, compared to a profit of $5.33 billion or $7.56 per share a year earlier.
Results included a one-time, $9.9-billion charge related to new U.S. tax laws.
Excluding one-time items, the company reported earnings of $9.70 per share but missed analysts' average estimate of $9.98 per share, according to Thomson Reuters I/B/E/S.
Alphabet's total spending jumped nearly 27 percent to $24.66 billion.
Total revenue rose 24 percent year-over-year to $32.32 billion, led by soaring sales of pricey online ads, an industry dominated by Alphabet and social media giant Facebook.
Google sells ad space on YouTube, its search engine and a variety of third-party platforms for anyone to display ads that lead users to watch video, install an app or visit a website.
Led by such ads, Google's advertising revenue rose 21.6 percent to $27.23 billion in the fourth quarter.
Alphabet on Thursday also named John Hennessy as chair of its board. (Reporting by Arjun Panchadar in Bengaluru; Editing by Sai Sachin Ravikumar)