Yum Brands Inc (YUM.N) posted a better-than-expected quarterly profit, helped by lower taxes, vigorous sales of Taco Bell's Naked Chicken Chalupas and lower costs at KFC restaurants.

Shares of the company were up 1.7 per cent at US$67.45 before the opening bell on Wednesday.

Sales rose eight per cent at Taco Bell restaurants open for more than a year, topping the 3.7 per cent growth expected by analysts polled by research firm Consensus Metrix.

The sales figure was boosted by $1 Double Stacked Tacos and the sale of more than 25 million Naked Chicken Chalupas, which are tacos in a fried chicken shell.

Chief Executive Greg Creed promised "more Naked products in the second quarter."

While KFC's same-store sales growth of two per cent missed analysts' estimates, its operating profit jumped 12 per cent on lower costs and as it sold more restaurants to franchisees.

Pizza Hut continued to struggle, reporting a three per cent drop in same-store sales, its third straight quarterly decline, even as rival Domino's Pizza Inc (DPZ.N) last week reported domestic growth of 10.2 per cent.

Yum and Pizza Hut franchisees this month struck a deal that includes corporate marketing and technology investments.

Yum Brands' income from continuing operations rose to US$280 million, or 77 cents per share, in the first quarter ended March 31, from US$226 million, or 54 cents per share.

Excluding items, the company earned 65 cents per share, beating the average analyst estimate of 60 cents, according to Thomson Reuters I/B/E/S.

Total revenue fell 1.8 per cent to US$1.42 billion as it sold more restaurants to franchisees but managed to beat Street expectations of US$1.35 billion.