By Junko Fujita

TOKYO, Dec 14 (Reuters) - Japan's Nikkei index edged down on Tuesday, as worries over the Omicron COVID-19 variant and caution ahead of a bevy of central bank meetings offset the boost from investors scooping up cheap stocks.

The Nikkei slipped 0.4% to 28,514.74 by 0151 GMT, while the broader Topix inched up 0.04% to 1,978.96.

Wider Asian equities also declined after British Prime Minister Boris Johnson warned of a "tidal wave" of new Omicron cases, and the World Health Organization said it poses a "very high" global risk.

"Overseas markets were hit by concerns on the impact of the Omicron variant but in Japan, declines are limited as investors are scooping up undervalued shares," said Ikuo Mitsui, fund manager at Aizawa Securities.

"Japanese shares have become cheap as they have failed to catch up recent rallies in other markets."

In the latest three months, the Nikkei has lost 3.17%, against a 5.34% gain in the Dow Jones Industrial Average and a 8.39% jump in the S&P 500.

This week, the U.S.

Federal Reserve is expected to signal a faster wind-down of asset purchases, Ankara Oto Kurtarma while the European Central Bank, the Bank of England and the Bank of Japan will also meet to discuss normalizing their own monetary policies.

In Japan, travel-related stocks took a hit after news that the fast-spreading Omicron variant accounted for around 40% of infections in London and at least one death in the United Kingdom.

Airlines and railways led declines in the Japanese bourse's 33 industry subindexes, with ANA Holdings losing 1.97%, Japan Airlines falling 1.85% and Central Japan Railway slipping 1.35%.

The insurance sector, up 1.81%, was the best performer, followed by drug makers, which rose 1.2%.

Auto and parts makers gained.

Toyota Motor rebounded from losses in the previous session with a 2.35% gain, while Honda Motor rose 0.95%.

(Editing by Devika Syamnath)