* Tech sector fall on worries about more regulations

* Trade worries still keep many investors cautious

* Bond yields fall globally

By Hideyuki Sano

TOKYO, March 28 (Reuters) - Asian shares pulled back on Wednesday as Wall Street was knocked hard on concerns about tighter regulations on the tech industry, denting a brief global equities recovery driven by hopes of easing fears of a trade war between China and the United States.

MSCI's broadest index of Asia-Pacific shares outside Japan fell 0.4 percent, with tech-heavy Korean shares falling 1.0 percent. Japan's Nikkei fell 2.1 percent.

On Wall Street, the S&P 500 lost 1.73 percent and the Nasdaq Composite dropped 2.93 percent, making their fourth decline in five sessions.

The tech sector were the worst hit as the industry came under more scrutiny, led by a 4.9 percent fall in Facebook , which has been embroiled in a scandal over the use of data by political consultants.

Nvidia was another weak spot, falling 7.8 percent after the chipmaker temporarily suspended self-driving tests across the globe after an Uber Technologies Inc autonomous vehicle killed a woman.

"There is a sense that there will be more regulations on Facebook or FANG and that the cost of compliance will increase," said Nobuhiko Kuramochi, chief strategist at Mizuho Securities.

Concerns about trade frictions between China and the United States also remain a drag even after reports of behind-the-scenes talks between Washington and Beijing spurred optimism that U.S. President Donald Trump's protectionist shift is more about gaining leverage in trade talks than isolating the world's biggest economy with tariff barriers.

In the currency market, the dollar changed hands at 105.39 yen, not far from Monday's 16-1/2-month low of 104.56, as the Japanese currency was supported by the risk-averse mood.

The euro lost steam after soft euro zone economic data and comments from European Central Bank policymakers flagging low underlying inflation.

Economic sentiment in the 19-countries sharing the euro slipped for the third month in a row in March while bank lending slowed.

Erkki Liikanen, ECB Governing Council member, said that underlying inflation in the euro zone may remain lower than expected even if growth is robust, so the central bank needs to remain patient in removing stimulus.

Another member, Jozef Makuch from Slovakia, also struck a similarly cautious tone.

The euro traded at $1.2407, off a three-week high of $1.24765 hit on Tuesday.

Germany's 10-year Bund yield hit two-month low of 0.500 percent, having taken a downward shift since hitting a 1-1/2-year high of 0.795 percent in Feb. 15.