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Alphabet the new parent company of Google, has reported profits up almost 50% for the third quarter.

Net income was $3.98bn, up from $2.74bn for the same quarter last year.

Google's revenue was $18.7 (£12.1bn) compared with $16.5bn.

Growth came mainly from mobile searches and YouTube users.

In August, the company created Alphabet as the new parent company of Google and its other diverse businesses.

In January, Alphabet will report Google's financial numbers separately from the other businesses, which include experiments with self-driving cars, investing in startups, making Internet-connected thermostats and searching for cures to health problems.

The break out of Google's figures are expected to reveal how much money Google would have made if it had not diverted money into chief executive Larry Page's so-called ``moon shots".

Alphabet shares were up 11% to $722.53 in after hours trading - a record, boosted by news of a large share buyback, which will means fewer investors in future who will therefore take a higher portion of any dividend payout.

Square root

YouTube announced on Thursday a plan to offer a monthly commercial free subscription service that will compete with Netflix and Amazon prime.

The company's board approved a plan to buy back a precise $5,099,019,513.59 in shares starting in the fourth quarter.

There has been speculation the number represented the square root of 26 - the number of letters in the alphabet.

Chief financial officer Ruth Porat acknowledged that was indeed the reference during a post-results conference.