Internet giant Google posted a 19% rise in group revenue to $15.42 billion in the first quarter, up from $12.95 billion over the corresponding quarter a year ago.

However, the figure missed market expectations in the $15.50 billion to $15.55 billion range. Giving details yesterday, Google said the number of 'paid clicks' by consumers on its ads rose 26% over the first quarter, while the average 'cost per click' fell by 9%.

Traffic acquisition costs, the levy that Google pays to partner websites running its ads, came in at $3.23 billion, or 23% of advertising revenue. Sales of digital media, including movies and games via Google Play store, as well as hardware devices, or what the company describes as 'other' revenue for accounting purposes, rose by 48% year-over-year to $1.6 billion.

Google's operating income slipped to 32% of group revenue on an adjusted cost basis as legal costs and the $3.2 billion acquisition of Nest, a manufacturer of smart thermostats, escalated corporate spending.

The company also posted a $198 million net loss from 'discontinued operations' which includes Motorola. The unit is earmarked for sale to China's Lenovo for $2.91 billion. In wake of the trading data, Google’s share price fell by 3% to $536.44 but bounced back above $540 in after hours trading.