Minutes show Fed officials unanimous in changing rates guidance

WASHINGTON/SAN FRANCISCO (Reuters) - Federal Reserve policymakers were unanimous in wanting to ditch the thresholds they had been using to telegraph a policy tightening, according to minutes of a meeting last month that shed little new light on what might prompt an interest-rate rise.

Minutes of the U.S. central bank's March 18-19 policy-setting meeting, Janet Yellen's first as chair, did not reveal any discussion of keeping rates near zero for a "considerable time," as the Fed mentioned in a policy statement issued after the meeting.

"(A)ll members judged that ... it was appropriate to replace the existing quantitative thresholds at this meeting," the minutes said.

"Almost all members judged that the new language should be qualitative in nature and should indicate that, in determining how long to maintain the current (low) federal funds rate, the Committee would assess progress, both realized and expected, toward its objectives of maximum employment and 2 percent inflation."

In the end, the Fed decided to drop its unemployment and inflation thresholds, and instead said it would wait a considerable time after ending a bond-buying program before finally raising rates.

But Yellen drew the most attention from financial markets when, in a post-meeting press conference, she defined "considerable time" as "around six months" depending on the economy - a comment that immediately depressed stocks and bonds.

(Reporting by Jonathan Spicer and Ann Saphir; Editing by Andrea Ricci)