U.S. Federal Reserve policy makers differed at last month’s meeting on how many more rate increases would be needed, according to the minutes from the Federal Open Market Committee’s Dec. 13, 2005 meeting.

“Views differed on how much further tightening might be required,” the FOMC minutes, released today, stated, noting that the monetary policy outlook “was becoming considerably less certain” and would “depend to an increased extent on the implications of incoming economic data.”

The FOMC voted unanimously last month to raise the U.S. Fed funds rate by a quarter percentage point for a 13th straight time to 4.25%.

In addition, “committee members generally anticipated that policy would likely need to be firmed further going forward,” the December minutes stated. Financial markets are pricing in another quarter-point rate increase, to 4.50%, at the FOMC’s next meeting on Jan. 31.

But signaling that the tightening campaign may be nearing an end, the FOMC dropped the longstanding “accommodation” descriptor it had used in its policy statements since it started raising rates in mid-2004.

The December minutes also noted that the central bank “would need to be mindful of the lags in the effect of policy firming on the economy.” That statement about the policy’s lagged effect wasn’t in the minutes of the FOMC’s previous meeting in November, and could signal a willingness on the part of officials to pause at some point and assess the impact of the tightening cycle on economic activity.