BEIJING (Reuters) - China's economy expanded 4.6% in the third quarter from a year earlier, official data showed on Friday, slightly beating analysts' expectations, maintaining pressure on policymakers as they consider more stimulus measures.

Economists polled by Reuters had expected third-quarter gross domestic product to have grown 4.5% from a year earlier, slowing from 4.7% in the previous three months.

Authorities have sharply ramped up policy stimulus since late September to revive the flagging economy and ensure growth will reach the government's target of around 5% this year.

On a quarter-by-quarter basis, GDP expanded 0.9% in July-September, slightly below expectations for a 1.0% rise and compared with a revised 0.5% gain in the previous quarter.