By Maggie Fick and Eva Mathews

LONDON (Reuters) -AstraZeneca raised its annual earnings forecast on Thursday, helped by strong demand for its cancer drugs, and reported third-quarter profit and revenue just ahead of analyst expectations even as COVID-19 vaccine sales evaporated.

The London-listed drugmaker now expects core earnings per share to increase by a low double-digit to low-teens percentage for the year, compared with a previous forecast of high single-digit to low double-digit percentage growth.

It also expects total revenue to increase by a mid single-digit percentage, compared with low-to-mid single-digit growth previously.

For the third consecutive quarter, strong sales of AstraZeneca's blockbuster cancer treatments and healthy demand for its drugs in emerging markets offset the loss of sales of its COVID-19 vaccine and therapy.

The Anglo-Swedish drugmaker - one of the strongest performers recently among listed European pharmaceutical companies - reported core profit per share of $1.73 for the third quarter, exceeding the $1.69 per share expected in a company-compiled consensus. Revenues of $11.49 billion came in just above the consensus forecast of $11.47 billion.

Shares rose 3.6% in early trade.

The results add to a string of strong quarters for Britain's biggest company by market capitalisation - worth 159 billion pounds ($195 billion) - bolstered by a strong pipeline of drugs.

AstraZeneca reports earnings in dollars. It said that in the first nine months of 2023, nine medicines delivered more than $1 billion in revenue.

Excluding sales of its COVID-19 products, third-quarter sales rose 12% to $2.96 billion in emerging markets on a constant currency basis.

Sales in China grew by just 1% on the same basis - the fifth consecutive quarter of growth, but below the 7% increase in the second quarter.

The company said there was some impact on Chinese sales from reduced promotional activities following the launch of a government anti-corruption campaign in July targeting the bribing of doctors in drug and medical equipment sales.

AstraZeneca is the largest foreign drugmaker in China, which accounted for 13% of last year's revenue.

The company also announced on Thursday it had bought an exclusive licence for an oral weight-loss drug candidate for up to about $2 billion from China's Eccogene, boosting its anti-obesity development work to participate in a booming market.

(Reporting by Maggie Fick in London and Eva Mathews in BengaluruEditing by Nivedita Bhattacharjee and Mark Potter)