* Dollar, yen gain as market optimism gives way to caution
* RBA holds rate meeting, close call on whether it will cut
* BOJ meets, seen assessing conditions but no major action TOKYO, April 7 (Reuters) - The yen and the dollar climbed on Tuesday, benefiting from defensive position-taking as a flush of optimism which powered a recent rally in stocks and higher-risk currencies gave way to caution about banks.
The yen had slid to its lowest in nearly six months against the dollar and euro on Monday but later revived as U.S. and European shares fell on renewed worries about the health of banks and the collapse of IBM's takeover bid for Sun Microsystems.
The Australian and New Zealand dollars, which have both ridden higher on improving risk appetite, also retreated from recent multi-month highs, with the market keen to see whether Australia's central bank cuts rates.
Analysts said there was both profit-taking after recent sharp gains and a renewal of risk-averse positions, with the dollar and the yen benefiting on safety bids when investor confidence wanes.
"It's a tendency since the financial crisis for investors to be risk averse, and they don't hold positions for a long time. As a result the theme in the market changes every week," said Toru Umemoto, chief FX strategist at Barclays Capital in Tokyo.
The euro fell 0.4 percent on the day to $1.3358 and 0.6 percent to 134.65 yen, after touching 137.42 yen on Monday, its highest since late October.
The dollar also slipped against the yen, falling 0.2 percent to 100.79 yen after climbing to 101.45 yen on Monday. Against a basket of major currencies it was up 0.2 percent.
The Reserve Bank of Australia (RBA) meets to decide whether to cut interest rates by 25 to 50 basis points or keep them steady at a record low of 3.25 percent, with the decision due at 0430 GMT.
The decision is seen as a very close call. The Australian dollar slid 0.5 percent to $0.7080 and 0.7 percent to 71.43 yen, after leaping to a six-month high of 72.87 yen on Monday, according to Reuters data.
The Bank of Japan ends a two-day meeting on Tuesday and is expected to keep interest rates unchanged at 0.1 percent.
But it may start lending against a wider range of municipal bonds to support regional banks, which are reeling in a domestic credit crunch and Japan's worst recession since World War Two.. (Reporting by Charlotte Cooper; Editing by Hugh Lawson)