DETROIT (Reuters) - Most Buick vehicles sold in the United States after 2016 could be imported from China and Europe, according to two sources familiar with parent General Motors Co's (>> General Motors Company) plans.

Only two of Buick's future U.S. models, replacements for the mid-size LaCrosse sedan and the large Enclave crossover, are expected to be built in North America, according to the sources, who did not want to be identified because their companies work with GM.

The increasing tendency of U.S. carmakers, including Ford Motor Co (>> Ford Motor Company), to shift more vehicle production to plants outside the United States is a hot-button topic in current contract talks with the United Auto Workers.

"We do not comment on future product speculation," a Buick spokesman said on Tuesday.

Buick is planning to shift production of the compact Verano sedan from Michigan to China in late 2016, the sources said. Production of the mid-size Regal sedan is likely to shift from Canada to either China or Europe in 2017, they added.

Buick is also planning to add two new U.S. models from overseas plants: The compact Cascada convertible, which will be imported early next year from Europe, and the compact Envision crossover, which will be imported from China in late 2016.

News of the U.S. arrival of the Envision, which went into production last year in China, was reported on Monday by Automotive News. Buick unveiled the Cascada earlier this year at the Detroit auto show.

One other Buick model, the subcompact Encore crossover, is currently imported from Korea. Production is eventually expected to shift to China, the sources said.

Buick is planning these production shifts as GM begins contract talks in Detroit with the United Auto Workers.

In Detroit, Cindy Estrada, head of the UAW's GM department, said the automaker would be "tone deaf" to import vehicles from overseas "after the sacrifices by U.S. taxpayers," as well as union concessions, to create a profitable GM after a government-funded bailout in 2009.

The LaCrosse is being redesigned next spring, with production moving to Hamtramck outside Detroit.

The Enclave is slated to be redesigned in early 2017. Production is expected to remain in Lansing, Michigan.

China is the largest market for the Buick brand, with sales last year of 919,582 vehicles, more than four times the 228,963 vehicles that Buick sold in the United States.

(Editing by Matthew Lewis)

By Paul Lienert and Bernie Woodall

Stocks treated in this article : Ford Motor Company, General Motors Company