British confectionery company Cadbury Schweppes confirmed on Monday that U.S. activist billionaire Nelson Peltz had increased his stake in Cadbury to around 4.5 percent from 3.47 percent.
Peltz increased his stake through his investment vehicle Trian.
The Financial Times newspaper said on Monday that Trian had recently teamed up with the Qatar Investment Authority (QIA) to boost its stake in Cadbury and keep pressure on the company to carry on improving its financial performance.
Cadbury, which plans to demerge its soft drinks business in the second quarter of 2008 to become a pure confectionery group, is scheduled to release a trading update on Tuesday.
The maker of Dairy Milk chocolate, Trident gum and Halls cough drops, decided in March to split off its Dr Pepper and 7UP drinks business with a sale to private equity buyers seen the most likely option. However, the auction was delayed in July following turbulence in world debt markets.
In October, Cadbury said it would focus instead on demerging the 7 billion-pound ($14.2 billion) North American soft drinks business and list it in New York rather than sell it off.
The Financial Times said on Monday that Trian is believed to support the plan to demerge rather than sell the drinks unit.
Shares in Cadbury were up 1.5 percent at 642.5 pence in early trading.