NEW YORK: Coca-Cola has gained a clear lead in the "cola wars", as regular and Diet Coke are now the top two brands in the US carbonated drinks sector.

Industry title Beverage Digest recently released data showing category sales fell 0.5% last year, to 9.4bn cases, a sixth successive annual contraction.

Demand is thus at a similar level as in 1996, meaning stealing share from rivals constitutes a primary means of driving growth in the $74bn (€52.2bn; £45.6bn) segment.

Coca-Cola Classic held 17% of sales in 2010, equating to 1.6bn cases, after posting a volume decline of 0.5%.

Pepsi-Cola's purchase rates decreased by 4.8% to 892m cases, losing 0.4% in terms of share, on 9.5%, as a consequence.

Benefitting from this trend, Diet Coke climbed to second with a 9.9% share, despite recording a 1% dip, to 927m cases.

Carlos Laboy, an analyst at investment bank Credit Suisse, suggested the impact of this trend could be profound.

"[I am] worried about the morale implications for PepsiCo's beverage people of having the company's namesake brand and its top beverage brand dropped to a tertiary spot," he said.

PepsiCo's overall share of the CSD sector slid by 0.6% to 29.3%, trailing Coca-Cola's 42%, Beverage Digest revealed.

Its current initiatives include creating natural sweeteners which contain fewer calories but give an enhanced taste, modifying packaging and adapting its product mix, having rolled out a "skinny" Diet Pepsi can last month.

Massimo d'Amore, chief executive of PepsiCo Beverages Americas, stated the firm was "totally committed" to regaining lost ground.

"We're not happy. We would obviously like to be number one," he said. "When my ancestors went from the Middle Ages to the Renaissance, they blew up the place, so that's what we are doing."

While schemes such as the Pepsi Refresh Project, an online effort letting web users vote for programmes promising to rejuvenate local communities, have broadened the brand's appeal, TV still offers specific advantages.

"We need television to make the big, bold statement," said d'Amore.

Alongside heightening TV support for its beverage portfolio by around 30%, incorporating a new campaign for its cola brand, Pepsi is spending an estimated $60m to sponsor reality series the X Factor.

Coca-Cola has been intrinsically associated with American Idol, which musical impresario Simon Cowell recently left to start a new show for the US, The X Factor.

"Our people, at the time, did not see how big 'American Idol' was going to be. We lost a lot of momentum and the competition gained it," said d'Amore.

"This is not a blind bet. We have huge confidence in Simon Cowell. He's learned a lot from 'American Idol', and the ratings outside the US for 'X Factor' have been very strong."

He added: "We are putting our marketing resources behind this show, so you shouldn't underestimate what we can do together to drive this property."

Speaking on a conference call with analysts in February, Muhtar Kent, Coca-Cola's chief executive, described its trademark brand as "the very oxygen of our business."

Coca-Cola's volume sales rose by 1% in North America during the last quarter, and Kent outlined his belief in the potential of the organisation's home market.

"These strong results ... are a testament to our long-held belief that through strong marketing and focused execution, we can accelerate our leadership position within North America," he said.

Data sourced from Beverage Digest, Los Angeles Times, Wall Street Journal; additional content by Warc staff