(Adds CEO comments, shares, Microsoft partnership; paragraphs 3-5,9,12)

By Aby Jose Koilparambil

May 8 (Reuters) - British events organiser Informa said on Wednesday it expects annual revenue and adjusted operating profit at the upper end of its previous forecast range, while increasing its share buyback programme by 160 million pounds ($199.8 million).

The world's largest exhibition group has benefited from the return of live events after a pandemic-led slump, and strong performance across its markets.

Chief Executive Stephen Carter said domestic-led business in mainland China, one of the group's major markets, was performing well.

"Our primary markets that we serve in China remain robust and there is the beginning of the return of international trade traffic to China which is material to the trade show business," Carter told Reuters.

He added the group was "definitely" seeing year-on-year growth in its Hong Kong business, amid a progressive increase in international travel and transit to the region.

The financial hub of Hong Kong is struggling to bounce back after a three-year lockdown for COVID-19 that saw many expatriates leave and tourist numbers dwindle, while high rents and a labour shortage now add to the pain.

Informa expects 2024 revenue at the top end of a range of 3.45 billion pounds to 3.50 billion pounds forecast in March.

Adjusted operating profit is also seen at the upper end of the prior forecast range of 950 million pounds to 970 million pounds.

Shares in the FTSE 100 firm were trading 2.5% higher by 0808 GMT.

In March, Informa raised its annual earnings forecast after 2023 profit more than doubled. The company expanded its share buyback by 47% to 500 million pounds as it continued to deliver strong performance through the first four months of the year.

Informa also said on Wednesday it had entered into a three-year access and partnership deal with Microsoft for use of artificial intelligence in its scholarly publishing business. ($1=0.8010 pounds) (Reporting by Aby Jose Koilparambil in Bengaluru; Editing by Subhranshu Sahu and Clarence Fernandez)