The advanced technology vehicle would have an extended driving range on battery power and would also have a diesel or gasoline engine that could power the car when the battery was low, the Detroit News said, citing unnamed GM officials.
Plug-in hybrids are gas-electric vehicles that can recharge their batteries with an extension cord and a normal wall outlet.
GM, which is trying to recover from a $10.6 billion loss in 2005 and stop a slide in U.S. market share, has been criticized for relying heavily on gas-guzzling sport utility vehicles. This year, it has also drawn sharp criticism for its decision to kill its EV1 electric car program.
The EV1 was introduced at the 1997 Los Angeles Auto Show and leased to selected customers. But GM pulled the plug on the project in 2002, citing insufficient public support.
The automaker eventually collected and destroyed almost all of the 1,000 EV1 cars, prompting the making of a documentary titled "Who Killed the Electric Car?"
The film was released this summer to wide acclaim from environmentalists and others concerned about the country's dependence on oil.
In an interview with Motor Trend published in July, GM Chief Executive Rick Wagoner said killing the $1 billion EV1 program was his worst decision. He said it did not affect the automaker's profitability, but did hurt its image.
The Detroit News said Wagoner will talk about GM's emphasis on advanced technologies in a speech he plans to deliver at the Los Angeles Auto Show later this month.
Other automakers are also researching plug-in technology, including Toyota Motor Corp. (TM), the world's leading producer of hybrid vehicles.
Honda Motor Co. Ltd. has also called for exploring plug-ins and is conducting advanced research on hydrogen.
Ford Motor Co. (F) has a fleet of hybrid hydrogen fuel cell vehicles as part of "real world testing of fuel cell technology."