* GM sales fall 0.3 pct y/y in May
* Sales decline 3.7 pct y/y in January-May
* GM phased out older Buick Excelle model (Adds context, Toyota and Nissan sales)
BEIJING, June 5 (Reuters) - General Motors Co on Monday said its sales in China fell in May for a second consecutive month, as the U.S. automaker phased out its older generation Buick Excelle in the high-volume small sedan segment.
The U.S. company, China's second-largest foreign automaker behind Volkswagen AG, sold 294,425 vehicles in May, 0.3 percent fewer than in the same month a year earlier.
In the first five months of the year, GM said its sales fell 3.7 percent to 1.48 million vehicles.
The automaker introduced the current generation Excelle GT in 2015 but until recently continued selling older Excelles at a discount to compete with lower-cost Chinese rivals.
Overall auto sales in China, the world's largest auto market, rose 4 percent for January to April, according to the China Association of Automobile Manufacturers, which has yet to report May data.
Analysts said the car market is normalizing after a steep rise in sales last year, due to a tax cut on small-engine vehicles that is now being phased out and leading to weaker year-on-year comparisons.
On Monday, Japanese competitor Nissan Motor Co Ltd said its May sales grew 5.7 percent. (Reporting by Jake Spring and Norihiko Shirouzu; Editing by Christopher Cushing)