* Key message will be similar to deputy governor’s latest remarks * Guidance may take form of loose range around BOJ’s 0% target * Clarifying BOJ’s preferred range will help stabilise markets * Current policy statement makes no mention of preferred range (Adds detail of expected debate at March review, background on YCC) TOKYO, March 12 (Reuters) - The Bank of Japan will likely insert clearer guidance in its policy statement on what it sees as an acceptable level of fluctuation in long-term interest rates, sources said, in an effort to show it won’t tolerate rises that hurt the economy. The move would be part of the BOJ’s review of its policy tools next week, which aims to make its stimulus programme more sustainable as the coronavirus pandemic pushes inflation further away from the bank’s 2% target. While there is no consensus within the BOJ, the guidance may take the form of a loose range around its 0% target for 10-year bond yields, said three sources familiar with its thinking. The key message would be similar to recent comments by BOJ Deputy Governor Masayoshi Amamiya that yields should be allowed to move more “as long as it does not diminish the effect of monetary easing”, they said. “What’s important is to clarify the BOJ’s stance it will not dial back stimulus,” one of the sources said, adding that including reference to a range in the statement was one idea. “It’s desirable to offer clearer guidance on the degree of fluctuations the BOJ will tolerate,” another source said. The review has drawn the close attention of markets as global recovery hopes push up yields in many economies including in Japan, challenging the BOJ’s efforts to cap 10-year yields at zero under its yield curve control (YCC) policy. Among the purposes of the review is to allow market forces to drive yields more and breathe life back into a market made dormant by heavy BOJ bond purchases - without sparking a jump in yields that could choke off a fragile recovery. CONFLICTING GOALS One focus of the review, to be held on March 18-19, is the fate of an implicit 40-basis-point band under which the BOJ allows 10-year yields to move around its 0% target. Markets began to interpret it as a BOJ line in the sand since Governor Haruhiko Kuroda mentioned it in 2018. But the band never made its way into the BOJ’s policy statement, which says only that yields are “allowed to fluctuate somewhat reflecting economic and price developments” - causing market confusion as to how forcefully the BOJ would defend it. Clarifying the BOJ’s preferred range in the statement, issued after each policy meeting, would help stabilise markets by removing uncertainty over its intentions, some analysts say. But critics warn that adopting a strict numerical range would run counter to the purpose of the review, which is to allow yields to move more freely around the bank’s 0% target. There is no consensus within the BOJ on how best to clarify its thinking on yield moves, with a final decision dependent on market moves leading up to the review, the sources said. With Japan’s economy still reeling from the pandemic, however, the BOJ is leaning toward maintaining the current band or stressing its lack of tolerance toward any abrupt spike in yields that hurts the economy, they said. After years of heavy purchases, the BOJ owns nearly half of the Japanese government bond (JGB) market and has successfully kept 10-year yields in a tight range around its 0% target. But market liquidity dried up as a result, forcing the BOJ to come up with ways to revitalise the bond market to make its YCC policy more sustainable. (Reporting by Leika Kihara; Additional reporting by Takahiko Wada; Editing by Catherine Evans)