* MSCI world index strains for best streak since 2003
* Asia-Pac index near 10-yr high, Nikkei lurches after high
* Tax plan worries weigh on dollar, kiwi rallies on RBNZ
* Crude oil steadies, gold hovers near 3-week high
LONDON, Nov 9 (Reuters) - Another impressive record for world stocks was hanging in the balance on Thursday, as a late blow-out in Japan and a subdued start in Europe threatened to spoil the longest winning streak for MSCI's global index since 2003.
Japans Nikkei saw a 2 percent swing down after hitting its highest since 1992 and most of Europe's main bourses drifted in and out of the red after mixed earnings and as Brexit talks resumed with low expectations in Brussels.
There were a series of ECB speeches and what should be buoyant new growth forecasts due later from the European Commission, though bond markets were mostly quiet following a rally this week in benchmark U.S. Treasuries and Bunds .
Germany's 10-year bond yield edged up for the first time in over a week and the euro and pound were both higher as the long-running saga of U.S. tax reforms weighed on the dollar.
Oil and Middle Eastern stock and bond markets also steadied after a nervy few days caused by a purge of royals and top officials by Saudi Arabia's Crown Prince.
"The stock market has run out of a little momentum since the blow-out on the (Japanese) topix so it feels like it's temporarily paused," said Societe Generale strategist Kit Juckes.
"We are waiting for some news from the Republicans on the tax plans, there is a bond market that has stalled and we've got rather soggy looking emerging markets... We probably need to get U.S. Treasury yields higher to get things going again."
MSCI's all-country equity index is clocking year-to-date gains of almost 19 percent.
But as a measure of relative calm of the current bull market and a reflection of the low volatility environment that has dominated all year, none of the latest 11 daily gains have exceeded half a percent and more than half of them were less than 0.1 percent.
Among currencies, the New Zealand dollar was the day's big mover, surging about 1 percent to a two-week high of $0.6974 before dipping to trade at $0.6956.
The kiwi soared after the Reserve Bank of New Zealand (RBNZ) said the country's fiscal stimulus and the currency's recent fall would lead to faster inflation and likely an earlier rise in interest rates.
On Thursday, the central bank held rates steady at 1.75 percent, as widely expected.
The dollar index against a basket of six major currencies was 0.1 percent lower at 94.803 meanwhile, as it drifted further from the three-month high of 95.150 set in late October.
A U.S. Senate tax-cut bill, differing from one already in the House of Representatives, was expected to be unveiled on Thursday, complicating a Republican tax overhaul push and increasing scepticism on Wall Street about the effort.
Some also focused on fallout from Democrat wins in regional U.S. elections this week as signal for next years mid-term Congressional elections for U.S. President Donald Trump.
"There's very much a risk of disappointment. The U.S. dollar could go through a weakening phase on the back of uncertainty around that tax reform," said Steven Dooley, currency strategist for Western Union Business Solutions in Melbourne.
In commodity markets, Brent and U.S. crude oil futures were little changed at $63.49 and $56.82 a barrel respectively, having hit two-year highs earlier in the week following a 40 percent surge since July.
U.S. data showing a rise in domestic crude production had weighed on sentiment overnight but the Middle East uncertainty in Saudi Arabia limited the losses.
Gold added 0.2 percent to $1,283.45 an ounce after rising to a three-week high of $1,287.13 an ounce the previous day.
Palladium hovered near a 16-year high of $1,019 while nickel fell by more than 2 percent in London to its weakest since October as hype over potential electric vehicle demand that has been driving it higher eased.
The nickel market had been ignoring downside risks from policy developments in supply markets Indonesia and the Philippines, and instead focusing on potential future demand from electric vehicle batteries, said Morgan Stanley in a report.
"We (have) heard little to alter our view that producing NiSO (nickel sulphate) isn't particularly challenging/costly and we see near-term downside risk to price," it said. (Additional reporting by Shinichi Saoshiro; editing by John Stonestreet)