National Australia Bank's (ASX:NAB) strategy appears to imitate that of the Commonwealth Bank of Australia (ASX:CBA), though a lackluster business banking unit has prompted a downgrade, Jarden said in a note on Thursday.

The bank's capital generation, earnings growth, and returns are relatively weaker than those of its peers, especially CBA and Westpac.

The company's business banking performance has weakened, challenging its "clear market leadership" claim.

Jarden said it does not view the bank's return and earnings growth profile as supporting its current valuation, leading to a downgrade of the stock to sell from underweight.

The price target of the bank was kept unchanged at A$29.