"Certainly, it's something we're considering," Duncan Aldred, vice president of the GMC brand, told CNBC when asked about the prospects of an all-electric version of the big Sierra pickup. While Aldred wouldn't confirm if development is already underway, he pointed to comments made by GM CEO Mary Barra last March that the carmaker is on a "path to an all-electric future."

While it is not clear how far along such plans have come, GM would join a growing list of automakers looking to electrify some of their biggest and brawniest vehicles. A senior Ford executive just last week confirmed that an all-electric version of the F-series pickup is now in the works.

With its CEO setting a goal of going 100 percent electric, General Motors is taking a close look at how, if not when, to offer an all-electric SUV, according to the head of the automaker's GMC truck brand.

The Ford F-150 Raptor was modeled in part off desert-racing trucks, and is best suited for "overland" off-roading as opposed to rock crawling.

A fully electric version of the GMC Sierra would likely be accompanied by a battery-electric version of the more mainstream, albeit higher-volume Chevrolet Silverado, said David Cole, director-emeritus of the Center for Automotive Research in Ann Arbor, Michigan. The trucks share the same underlying platform, as well as conventional internal combustion powertrains. That would increase economies of scale and bring down the cost of developing and producing a battery drive system, several industry observers pointed out.

"They wouldn't be saying this if they weren't really confident about doing it," Cole said. After having spent time at the GM battery lab recently, Cole said the automaker "wants to be at the forefront of battery-electric technology."

But several key issues are driving the company's pace of product development, including the need for batteries that can deliver better range and come down in price. When the Chevrolet Bolt EV launched in late 2016, product development director Mark Reuss — now GM's president — said it had driven the cost of battery cells down to around $145 a kilowatt-hour. Cole said GM's target is "lower" than $100, a figure that could put its future all-electric drivetrains close to parity with comparable diesel and gas technology. Battery cells generally cost $150 to $200, according to estimates from researchers at Boston Consulting Group.

How soon that would happen is unclear. For his part, GMC chief Aldred told CNBC that battery technology still carries a fairly hefty premium that makes it difficult to target mainstream segments, unless a carmaker like GM is willing to accept lower margins. As a result, the executive said, automakers would likely target higher end products.

Pickups, on the whole, carry some of the highest profit margins in the auto industry, particularly some of those sold through the GMC brand. But the entire industry has been pushing pickups up-market, adding on more options and luxury touches to drive up the price. Ford is now offering a version of its F-Series loaded with luxury car features that carries a price tag nudging $100,000.

"It's always a mistake to introduce a new technology on a lower-priced product," said Cole. "You have a better opportunity to cover costs if it's on a high-end vehicle."

Ford has not offered any details about the planned all-electric pickup that was announced by its president of global operations at a conference in Detroit last week. But Cole and others believe it will also target a premium, personal use segment of the market, rather than more traditional, commercial users, such as builders and contractors.

Detroit automakers continue to dominate the full-size pickup segment and offer a broader range of options, including powertrains, than import rivals. Company officials have not said whether the third domestic manufacturer, Fiat Chrysler, will also launch an all-electric model, though during a media event at the North American International Auto Show last week, CEO Mike Manley indicated the company will be expanding its electrified portfolio.