As part of General Motors’ announcement today that it plans to increase production at its Orion Assembly Center in Michigan, the automaker spilled the beans on the official name of its new compact car: Buick Verano.

We’ve known about the Verano for a while – it’s essentially a domestically-assembled version of the Chinese-market Buick Excelle, itself based on the same Delta II platform as the Chevrolet Cruze. But what we haven’t known is its official name.

Slotting beneath the Regal in Buick’s lineup, the new compact sedan will be based on GM’s Delta II architecture, the very same that underpins the Chevrolet Cruze and Opel Astra.

Although the Verano is very similar to the Excelle recently unveiled in China, the true roots go back to the Opel Astra – with which it shares many components. In fact, the Chinese-market Excelle’s interior is lifted almost directly from the German-designed Astra.

As with any new model riding on GM’s Delta II platform, expect a range of fuel efficient powertrain offerings, including the 1.4-liter turbo-charged engine with 138 horsepower (the optional engine in the Cruze), and possibly a high-end 1.6-liter turbo-charged four-cylinder with around 180 ponies. A six-speed automatic transmission is a given; a base six-speed manual is possible but unlikely.

Given that the Verano will ride on the same platform as the Volt, there is also a possibility that the Volt’s powertrain could make its way into the Buick.

The compact Buick sedan should hit dealers by mid-to-late 2011 with a price tag around the $20,000 mark.