UPDATE 1-Australia's NAB H1 falls, outlook bearish

* National Australia Bank H1 profit falls 9.4 pct, in line

* Australia's biggest lender warns of worsening outlook

* Bad debt charges to rise at home as unemployment grows (Adds CEO quotes, details, background)

SYDNEY, April 28 (Reuters) - National Australia Bank (NAB.AX) (NAB), the nation's top lender, reported a 9.4 percent fall in first-half cash profit on Tuesday, in line with expectations, but it forecast tougher times ahead as bad-debt charges balloon.

Australian banks have avoided the banking disasters that have swept other developed nations but they now face a slowing home economy, higher wholesale funding costs squeezing their lending margins, lower mortgage growth and rising bad debts.

"I think we are seeing the play-out now of what has been a challenging economic environment but we take some comfort from the fact that it's a solid result taken in global context," Chief Executive Cameron Clyne said in releasing the results.

"2009 will be characterised by bad and doubtful debts on the business side of things. 2010 will begin to move into the consumer side as unemployment begins to peak," he added.

Last month, NAB said it would cut its first-half dividend by 25 percent, its first payout cut since 1991, becoming the second local bank to cut its dividend in the current recession.

In February, Australia and New Zealand Banking Group (ANZ.AX), the fourth-largest lender, became the first of the top four local banks to announce a dividend cut since the early 1990s.