NEW YORK -- China's Luckin Coffee has raised $150 million from investors led by BlackRock, the Starbucks challenger said Thursday, lifting the valuation of the startup to $2.9 billion. A fund managed by BlackRock, the world's largest asset management firm, contributed $125 million to the round, Beijing-based Luckin said. The new war chest will help Luckin advance its aggressive expansion, which aims to snatch Starbucks' crown of China's largest coffee chain, and will intensify the competition in the traditionally tea-drinking nation.