(Adds share movement in paragraph 1 & 7)

Aug 9 (Reuters) - TP ICAP announced a 30 million pound ($38.30 million)share buyback and reported a rise in half-year profit on Wednesday, as it kept a tight lid on costs and saw more stable energy markets, sending shares in the world's biggest inter-dealer broker up almost 14%.

Energy markets have normalised following a challenging 2022, when heightened geopolitical uncertainty led to a pronounced reduction in trading volumes, the company said.

The energy and commodities division reported a 12% increase in revenue for the six months ended June 30.

"Central banks are committed to deploying monetary policy to combat inflation; energy markets are normalising. These trends benefit our Global Broking and Energy & Commodities divisions," TP ICAP said.

The London-listed company reported an adjusted profit before tax of 146 million pounds ($186.33 million) for the six-month period, compared with 116 million pounds a year ago. This is in line with a company-compiled consensus, according to J.P Morgan analysts.

The British company, which was born out of the merger of brokers Tullett Prebon and ICAP, also announced a share buyback, after it said the 100 million pounds of cash targeted in the first half last year had been freed up 6 months ahead of schedule.

Shares in TP ICAP jumped to 176 pence in morning trade, set for its biggest one-day percentage gain since March 2020.

The company proposed an interim dividend of 4.8 pence per share, compared with 4.5 pence last year.

Still, revenue edged 1% higher to 1.13 billion pounds, coming off a strong comparable period last year, when trading platforms saw a revival in volumes and client activity levels as the Ukraine war and risks of a recession due to tightening monetary policies kept financial markets volatile.

($1 = 0.7833 pounds) (Reporting by Eva Mathews in Bengaluru; Editing by Sherry Jacob-Phillips and Louise Heavens)