(Reuters) - Australia's Westpac Banking Corp reported a 16% drop in its first-half net profit on Monday as margins are squeezed by intense lending competition and higher costs. It also announced an increase of A$1 billion to an existing share buyback program.

The country's No. 3 lender in terms of market value said its net profit was A$3.34 billion ($2.21 billion) for the six months ended March 31, compared with A$4.00 billion a year earlier.

That slightly missed Visible Alpha consensus estimate of A$3.43 billion compiled by UBS.

($1 = 1.5133 Australian dollars)

(Reporting by Sameer Manekar and Rajasik Mukherjee in Bengaluru; Editing by Lisa Shumaker)