Falling demand for SUVs and pickups plus uncertainty over future fuel economy and emissions standards has forced GM to delay all future designs of its SUV and fullsize truck models while product planners focus on building lighter and more fuel-efficient vehicles. In the meantime, the product life-cycle of GM’s current pickup and SUV models will be extended until market conditions change for the better.

GM is looking at the “whole product portfolio” as attempts to adapt to shifting market trends and rising fuel prices, company spokesman Tom Wilkinson explained to the Wall Street Journal. The review will lead to a drop in GM’s profits and is expected to slow the carmaker’s future revenue generation, Wilkinson added.

Mr. Wilkinson said GM is considering how it can effectively supply the U.S. market with fuel-efficient cars it currently sells overseas. Sources close to GM also revealed that a future Hummer produce will be cancelled and there’s the chance that another brand could be axed altogether.

GM has already confirmed plans to drastically cut its SUV and truck production and replace these with more car models, and most other manufacturers in North America, including Ford, Chrysler, Toyota and even Honda, have announced similar plans.