TOKYO, Nov 20 (IFR) - Japanese government bond prices were steady to slightly lower on Wednesday in thin trading as investors awaited the outcome of the Bank of Japan's two-day policy meeting on Thursday.

The yield on the new 20-year JGBs auctioned on Tuesday as a re-open of issue number 146 moved in a narrow range between 1.505 percent and 1.510 percent, and was last at up 0.5 basis point at 1.505 percent.

The 20-year JGBs remained firmer compared with the average accepted yield of 1.514 percent in Tuesday's sale, as a few life insurers continued to buy them on dips in thin trading, anticipating that the BOJ will continue to buy superlong JGBs under its asset purchase program.

On Wednesday, the BOJ offered to buy 200 billion yen ($2 billion) of JGBs maturing in more than 10 years, in addition to 600 billion yen in the 1-year to 5-year zone. The BOJ bought JGBs in the same zones and amounts on Oct 23, a day after last month's 20-year JGB auction.

Other domestic real money accounts stayed largely on the sidelines ahead of Thursday's BOJ policy decision. The central bank is expected to maintain its ultra-loose monetary policy and debate how weak exports and swinging expectations about when the U.S. Federal Reserve will cut its stimulus may affect Japan's economic recovery.

The yield on the current 5-year JGB was unchanged from Tuesday at 0.20 percent, while the 10-year yield was down half a basis point at 0.610 percent.

In the superlong zone, the 30-year yield added half a basis point to 1.660 percent ahead of next Tuesday's quarterly 40-year JGB auction.

Lead Dec JGB futures moved in a 144.86-144.97 range, finishing the morning session down 0.06 point at 144.90, and were last down 0.01 point at 144.95.