May 3 (Reuters) - Westpac Banking Corp laid out a three-year plan to cut costs on Monday as its first-half cash earnings more than tripled from last year's plunge.

Australia's second-largest bank said cash earnings for the six months ended March 31 rose to A$3.54 billion , compared with A$993 million last year. This was above a forecast of A$3.28 billion in a Reuters poll.

($1 = 1.2960 Australian dollars) (Reporting by Rashmi Ashok and Nikhil Kurian Nainan in Bengaluru; editing by Diane Craft)