(Updates at 0600 GMT)

TOKYO, May 17 (Reuters) - Japan's Nikkei share average

snapped a three-day winning streak to end lower on Friday,

tracking Wall Street's lacklustre overnight finish, while

uncertainties over the Bank of Japan's policy trajectory also

weighed on sentiment.

The Nikkei slipped 0.34% to close at 38,787.38, but

gained 1.43% for the week.

The index recouped some losses after the BOJ maintained

the amount for its regular bond-buying operation.

The central bank on Monday abruptly reduced the amount for

bonds with 5-10 years left to maturity, raising speculations

that it would continue its hawkish move.

"The market eyed the BOJ operation today because that was

part of the gauge for its policy path," said Yugo Tsuboi, chief

strategist at Daiwa Securities.

The broader Topix recouped early losses to end 0.3%

higher at 2,745.62 and posted a 0.64% weekly gain.

"Investors continue to scoop up cheap stocks as they see

the market rising further towards the end of this year," said

Jun Morita, general manager of the research department at

Chibagin Asset Management.

On Thursday, U.S. stocks closed lower after the Dow

reached an intraday high of 40,000 for the first time, as

investors continued to recalibrate their rate-cut expectations

following data showing a slowdown in inflation. The Philadelphia

SE Semiconductor Index lost 0.55%.

In Japan, chip-related shares fell on Friday, with Tokyo

Electron ( TOELF ) losing 2.01% to become the biggest drag on the

Nikkei. Silicon-wafter maker Shin-Etsu Chemical ( SHECF ) fell

1.52%.

Toyota Motor ( TM ) rose 2.51% to become the biggest boost

for the Topix. Mitsubishi UFJ Financial Group ( MUFG ) and

Sumitomo Mitsui Financial Group ( SMFG ) gained 2.04% and 3.44%,

respectively.

The banking sector rose nearly 2% to become the

top performer among the Tokyo Stock Exchange's 33 industry

sub-indexes.