LONDON - A relief rally in the dollar faded on Thursday, with the greenback holding on to only minor gains against major peers after rallying on news that a court blocked U.S. President Donald Trump from imposing import tariffs on other countries.

The initial boost to the dollar from the court ruling started to fade during London trade as market attention returned to a still uncertain trade outlook and worries about the U.S. fiscal outlook.

The dollar was last up just 0.1% at 145 yen, down from two-week highs touched earlier, trimmed gains against the Swiss franc to stand 0.1% higher at 0.8278 and was virtually flat against the euro.

"Perhaps people are reconsidering the headlines in that President (Donald) Trump still has the route to pursue sectoral tariffs - if he can't pursue these broader, more unilateral tariffs because of the court ruling," said ING's Head of Markets Research Chris Turner.

"Equally there's the issue with regard to if tax tariff revenues are constrained, then it creates more focus on the fiscal issues the U.S. faces this summer."

The trade court ruling found Trump had overstepped his authority by imposing across-the-board duties on imports from U.S. trading partners.

"Reciprocal tariffs are off for now, but this should not alter the medium trend. Trump may find other methods to impose his economic and trade agenda, so in that respect it's uncertainty squared," said Kenneth Broux, head of corporate research FX and rates at Societe Generale.

U.S. assets including the dollar have been hurt in recent months as investors reassess historic assumptions around the strength of U.S. markets given an erratic trade policy and concern about high debt.

In a note, Scotiabank FX strategists said that the court decision and likely appeal extend the uncertainty surrounding tariffs and business decision-making, keeping a brake on global trade.

Sterling was one of the few major currencies trading up against the dollar, gaining 0.1% to around $1.3470.

The dollar index, which measures the U.S. currency against six major peers, was at 99.904 after earlier rising above 100 for the first time in a week.

It remains down some 8% so far this year.

The greenback has weakened about 2% against the yen, nearly 6% against the Swiss franc and 4% against the euro since Trump slapped harsh levies on global economies on April 2.

U.S. Treasuries also sold off on Thursday, with 10-year yields up 4 basis points at 4.52%.

Europe's benchmark STOXX 600 index was up 0.3%, and U.S. stock futures jumped on a risk-on rally.

Global investor sentiment was also lifted this week after Trump delayed at the weekend his plan to impose 50% tariffs on European Union imports, and investors are on the lookout for any signs of improving relations between the United States and its trade partners.

Traders meanwhile cut their expectations for Federal Reserve interest rate cuts to 42 basis points of easing compared with 50 basis points earlier in the week, LSEG data showed. (Reporting by Rae Wee, Stella Qiu, Johann M Cherian, Lucy Raitano and Ankur Banerjee; Editing by Christopher Cushing, Jamie Freed and and Giles Elgood)