Google parent Alphabet sold more ads and kept costs under control, actions that increased the company's sales and profit in the latest quarter. The growth allowed the company to introduce its first share buyback and beat Wall Street's profit forecast on Thursday.

The company's bottom line was boosted by strong gains in mobile search and YouTube advertising, while it kept a tight lid on expenses.

"Our Q3 results show the strength of Google's business, particularly in mobile search. With six products now having more than 1 billion users globally, we're excited about the opportunities ahead of Google, and across Alphabet,” said Ruth Porat, CFO of Alphabet and Google.

Third-quarter revenue rose to $18.68 billion from $16.52 billion a year earlier.

Net income rose to $3.98 billion, or $5.73 per Class A and B share, from $2.74 billion, or $3.98 per share in the same quarter last year.

Excluding one-time items, the company earned $7.35 per share.

Expenses rose 9.1 percent to $13.97 billion but were 74.7 percent of total revenue, compared to 77.4 percent in the same quarter last year.

The company said advertising revenue increased 13 percent to $16.78 billion in the three months ended Sept. 30, while the number of total paid clicks rose 23 percent, compared to an 18 percent increase in the previous quarter.

Cost-per-click, or the average price of online ads fell 11 percent in the quarter.

The results are the first since Google officially changed its name on Oct. 2 as part of an overhaul of its operating structure, with Alphabet acting as a holding company. Under the restructuring, search, advertising, maps, YouTube and Android will remain part of Google.