General Motors Corp. signs a multi-year agreement worth more than $800 million to export Buick Enclave cross/utility vehicles and other models and components to China beginning in 2008.

“These new Buick premium (cross/utility) vehicles will strengthen our lineup and enable us to continue to meet the changing needs of our growing base of customers,” says Ding Lei, president of Shanghai GM, the auto maker’s joint venture in the region.

GM says the deal covers a 4-year period and is expected to include 15,000-20,000 Enclaves. Shanghai GM will sell the vehicles in its 400 dealerships throughout China.

In May the auto maker signed a $700 million agreement with the Chinese government to export Cadillacs and automotive components to the country from the U.S. The components support the shipped vehicles. In the last 10 years, GM’s operations in China have imported about $3.5 billion worth of vehicles, components, equipment and machinery from North America.

The news arrives on the same day United Auto Workers union members employed by GM in the U.S. walk off the job nationwide. The two sides failed to negotiate a tentative contract before a deadline imposed by the union. Job security is the primary issue standing between GM and a contract settlement, the union says, and GM’s key bargaining chip is thought to be the threat of moving jobs overseas to countries where the labor is less costly.

A GM spokesman says there is no connection between the timing of the announcement of the newly signed agreements with China and the strike against the auto maker.

“The signing has been in the works for quite a while and it coincides with the visit of China’s Assistant Vice Minister of Commerce to Washington,” the spokesman says.

GM builds the Enclave and its Lambda platform mates, the GMC Acadia and Saturn Outlook, at its plant in Delta Township, MI. The plant added a third shift earlier this month to meet demand for the CUVs.