BRIEF-3M CEO says "economic environment has changed" since the company adopted its long-term 7-8 percent organic revenue growth target, now views that range as "stretch target"

BOSTON, Sept 19 (Reuters) - 3M Co : * CEO says "economic environment has changed" since the company adopted its

long-term 7-8 percent organic revenue growth target, now views that range as

"stretch target" * CEO expects "fewer, but slightly bigger" acquisitions by company in future * CFO says company working to address U.S. justice department's objections to

planned Avery Dennison Corp office products group acquisition, but "we have a contract that

remains in place"