Hyundai Motor Co and affiliate Kia Motors Corp aim to lift global vehicle sales by 2.5 percent in 2015, as capacity constraints and a weak market recovery set up the South Korean pair for their slowest expansion in 12 years, reported Reuters.

Hyundai-Kia, together the global No.5 automaker, have seen their sales growth slow since their record expansion in 2010 as factories reach full strength and competition rose at home and in key markets like the United States.

Hyundai Motor said on Tuesday it would build two factories in China, its first new manufacturing plants since 2012, but that they would not go into production until later 2016.

For 2015, the pair aims to sell 8.2 million vehicles - 5.05 million for Hyundai alone - versus the 8.27 million average forecast of five analysts polled by Reuters.

The duo offered conservative sales targets and beat them in recent years. In 2014, sales rose 5.8 percent to 8 million vehicles, versus its earlier target of 7.86 million due mainly to strength in China and other emerging markets.

"I expect to comfortably achieve our sales target this year," Chung Mong-koo, chairman of the family-run conglomerate, said in a New Year speech to employees on Friday.

The global vehicle market is likely to grow 3.9 percent this year, versus 3.5 percent expansion in 2014, as recovery in emerging markets outside of Russia offsets sluggishness in the United States and Europe, said a Hyundai think tank.

"There is still uncertainty about what's going to happen to Russia," Hyundai-Kia Executive Vice President Park Hong-jae, who heads the Korea Automotive Research Institute, told reporters last week.

Shares of Hyundai Motor fell 29 percent in 2014, a year of sluggish earnings and investor outrage over a $10 billion property purchase in Seoul. Kia shares fell 7 percent versus a 5 percent decline in the broader market.