(corrects highest ever FTSE closing level in par 3)
* Investors await FED minutes on stimulus measures
* Kazakmys and ENRC fall on bid uncertainty
* ARM falls post investor day on earnings uncertainty
* Lloyds rises as it allays fears of an equity raise
By David Brett
LONDON, May 22 (Reuters) - Britain's FTSE 100 weakened early on Wednesday after hitting 13-year highs in the previous session, as investors looked for further clues from the U.S. Federal Reserve over the outlook for its stimulus measures.
London's blue chip index fell 16.89 points, or 0.3 percent to 6,786.98 at 0807 GMT.
Its close on Tuesday of 6,803.87 was its highest since its record close in late 1999 (6,930.20), with equities partly driven by the loose monetary policy which has driven down yields in other asset classes.
Despite two senior Fed officials playing down the chances of the central bank signaling a readiness to trim its bond buying programme, some investors remain cautious.
Fed chairman Ben Bernanke is due to testify to Congress later in the session, while the minutes from the Federal Open Market Committee's April 30-May 1 policy meeting will be released at 1800 GMT.
"Given the chairman's previous emphasis on the employment to population ratio, there would seem little reason for him to hint at any meaningful tapering of purchases this year. Nevertheless that is what the market expects," Guy Foster, head of portfolio strategy at Brewin Dolphin (LSE: BRW.L - news) , said.
The FTSE was little changed after the release of Bank of England minutes showing policymakers remained split 6-3 against restarting bond purchases in May, and of public sector borrowing figures and lower-than-forecast April retail sales data.
BoE governor Mervyn King was among the minority favouring more asset purchases. His successor Mark Carney, who joins the bank in July, warned on Tuesday that Europe could face a decade of stagnation unless it makes big reforms, and should heed the lessons of Japan, which is undertaking bold monetary stimulus. [IDD:nBELMGE90W]
Leading Wednesday's fallers were miners Kazakhmys (LSE: KAZ.L - news) , down 5.7 percent, and Eurasian Natural Resources, down 4.6 percent. Kazahkmys already holds a stake in ENRC and is considering a potential cash-and-share buyout bid.
UBS (Xetra: UB0BL6 - news) cut its rating on Kazakhmys to "neutral" from "buy" saying it sees a high probability of an increased offer for ENRC after an initial proposal of 260 pence per share was rejected by ENRC's independent committee, with 300-350 pence more realistic.
Chip designer ARM fell 2.8 percent following its investor day with traders citing various reports heightening concerns over its earnings outlook including Intel Corp's creation of a unit aimed at growing its market share in mobile technology.
Lloyds Banking Group (LSE: LLOY.L - news) was the standout gainer, up 2.4 percent, after it allayed concerns it might have to raise fresh equity by saying that it would be able to meet new capital requirements.
(Reporting by David Brett; Editing by Catherine Evans)