(Reuters) - National Australia Bank on Thursday posted an about 13% drop in its first-half cash profit as the country's no. 2 lender grappled with high operating costs and cutthroat competition.

NAB, also the country's top business lender, posted cash earnings of A$3.55 billion ($2.32 billion) for the six months ended March 31, compared with A$4.07 billion a year ago.

That was in line with the Visible Alpha consensus estimate of A$3.55 billion compiled by UBS.

($1 = 1.5330 Australian dollars)

(Reporting by Sameer Manekar and Poonam Behura in Bengaluru; Editing by Anil D'Silva)