Taco Bell Doritos: There's a 'Taco Bell' flavor. Really.

Frito-Lay wants a bigger bite of Taco Bell's popular Doritos Locos Tacos.

The snack food giant plans to roll out its Doritos in a "Taco Bell" flavor as a limited-time product this spring, aiming to capitalize on the popularity of the Doritos-flavored tacos introduced by the fast-food chain last year.

Frito-Lay says it will be the first time since the 1990s that it has offered Doritos branded with the logo of a national restaurant chain.

Nacho Cheese Doritos Locos Tacos has been one of the biggest new menu items in recent times, with Taco Bell selling more than 300 million of the tacos with flavored shells since their introduction in March.

They were such a hit that Taco Bell postponed a follow-up Cool Ranch flavor to early this year to make sure there was enough capacity to make the shells. The chain also plans to introduce a taco in "Flamas" flavor, a Doritos variety available only in select regions of the country.

The offerings reflect the unique bonds between Yum Brands Inc., which owns Taco Bell, and PepsiCo Inc., which owns Frito-Lay. PepsiCo spun off Taco Bell, KFC and Pizza Hut more than 15 years ago, but the three chains still serve PepsiCo drinks, and executives collaborate in other ways to boost their respective fortunes.

The idea for the Doritos Locos Tacos, for example, came about in early 2010 when Taco Bell CEO Greg Creed visited Frito-Lay executives in Plano, Texas, to discuss how to celebrate the chain's upcoming 50th anniversary in 2012. Since Frito-Lay didn't have a production line for the flavored shells at the time, the Doritos seasoning was sprayed onto regular taco shells so executives could get of sense of how they'd taste. Creed said he knew right away it would be a hit.

"You know you've got a big idea when you don't have to explain it," said Creed, who has been with the restaurant chains since they were owned by PepsiCo. Creed noted that the mutual trust between the companies meant the project was based on "a handshake" in the early days.

Doritos Locos Tacos now account for about a quarter of all taco sales at Taco Bell, according to Creed. Without giving details, Frito-Lay North America Chief Marketing Officer Ann Mukherjee said in a separate interview that Doritos Locos Tacos have also boosted sales volume for Frito-Lay, which supplies taco shells for Taco Bell.

A variety of flavors were tested for the Doritos Locos Tacos before executives settled on Nacho Cheese, which is by far the most popular Doritos flavor (Cool Ranch is second). But Frito-Lay didn't want its Doritos name on just any taco shell, so it created a special, crunchier shell for the Doritos Locos Tacos.

"They wanted it to have that teeth-rattling crunch," Creed said.

To mimic the taste of Doritos Locos Tacos, Mukherjee said the Taco Bell-branded Doritos this spring will be a combination of Nacho Cheese flavor and taco flavor. Frito-Lay plans to release a Cool Ranch Taco version at the same, which could be intended to capitalize on the much-anticipated rollout of Taco Bell's Cool Ranch shells. Taco Bell hasn't specified when it will release its Doritos Locos Tacos in that flavor, however.

The partnership is likely to continue paying off for both companies, with Creed saying Taco Bell plans to keep looking for new Doritos flavors for its tacos. Taco Bell also works with PepsiCo to offer unique soft drinks, such as Mountain Dew Baja Blast.

The enduring relationship between PepsiCo and Yum was even captured in an exchange on Twitter last fall when Pepsi tried to engage customers on Twitter by asking them to fill in the blank: "After school snack: Pepsi and ______."

Taco Bell responded with the suggestion, "Taco Bell."

Pepsi shot back with, "There's no better answer. (hash)truth."

The exchange was mocked by the website BuzzFeed as "The Saddest Moment in Twitter History," but it also highlights the unusual ties between the two companies.