Jan 30(Reuters) - United Parcel Service reported a 31.8% drop in quarterly profit on Tuesday, as e-commerce demand remained subdued and costs jumped from the company's new contract with the Teamsters union.

The world's biggest package delivery firm reported an adjusted profit of $2.47 per share, for the fourth quarter ended December, down from $3.62 per share, a year earlier.

(Reporting by Ananta Agarwal in Bengaluru and Lisa Baertlein in Los Angeles; Editing by Sriraj Kalluvila)