Investor Nelson Peltz has increased his stake in soft drinks group Dr Pepper Snapple, via private investment group Trian Fund Management.

Peltz, who is CEO and a founder of Trian, has built up a 7.18% stake in Dr Pepper Snapple, according to a filing by both groups last Friday.

Trian said the move has been made because Dr Pepper Snapple's (DPS) shares "are currently undervalued in the market place and represent an attractive investment opportunity".

Peltz first acquired a stake in the firm in 2006, when it formed part of the Cadbury Schweppes group. His decision to raise the stake will be a confidence boost for a soft drinks industry under pressure from the US economic slowdown. 

"The Trian Group sees opportunities to create value through sharper strategic focus, better operational execution and more efficient uses of capital," Trian said.

It added that investors tended to view DPS as "more of a beverage bottler than a branded beverage company", even though bottling only contributes to around 5% of the firm's underlying operating profit. DPS is the third largest soft drinks group in the US.

Analyst Mark Swartzberg, of Stifel Nicolaus, agreed with Trian that the market view of DPS was "too negative".

In a note today, Stifel Nicolaus continued to recommend DPS shares, although reduced earnings estimates for the firm, as well as for The Coca-Cola Co and Pepsi Bottling Group.