By Asha Sistla

(Reuters) - Palladium soared to an all-time high on Friday, with producers locking in stocks of the auto-catalyst metal squeezed by a sustained supply shortage, while gold firmed en route to its first weekly gain in four supported by Middle East tensions.

Palladium <XPD=> rose 0.9% to $1,637.13 an ounce as of 1:44 p.m. EDT (1744 GMT), having touched a record $1,654.56. The metal was up 2% so far for the week, on track for a seventh straight weekly gain.

"Modest producer hedging and speculative interest in an extremely illiquid market has driven borrowing costs in the metal sharply higher," said Tai Wong, head of base and precious metals derivatives trading at BMO.

"Last Friday it cost perhaps a percent to borrow for a month [annualised], today it has been borrowed at 5%. The market has been and remains in fundamental deficit, so conditions are likely to remain tight for some time."

The price of palladium, used mainly in emissions-reducing catalysts for vehicles, has surged about 30% this year.

"Fundamentals have not changed but no one buys way in advance. They buy when they need, typically manufacturers. So manufacturers have come in and done some long-term hedging, driving the price high," said an analyst based in New York.

"And when a trend starts occurring like that, then you have the industries jumping on the bandwagon, which drives it even higher."

Spot gold <XAU=>, meanwhile, gained 0.6% to $1,508.63 per ounce, up about 1.5% so far this week. U.S. gold futures <GCcv1> settled up 0.6% at $1,515.10.

"It's a bullish consolidation we see," said Fawad Razaqzada, market analyst with Forex.com, adding that bullion is also being supported by safe-haven interest driven by tensions in the Middle East.

The United States said it was imposing sanctions on Iran's national bank after last weekend's attack on Saudi Arabian oil facilities. Iran denies involvement in the attack.

The Federal Reserve cut interest rates for the second time this year on Wednesday but gave mixed signals on future rate cuts.

Lower interest rates reduce the opportunity cost of holding non-yielding bullion and weigh on the dollar, making gold cheaper for investors holding other currencies.

"(The) Global outlook still looks quite unfavourable and central banks around the globe will continue to ease monetary policy, which will be beneficial for gold," said FXTM analyst Lukman Otunuga.

Markets also focussed on U.S.-China trade talks in Washington before high-level discussions next month.

Silver <XAG=> firmed 0.3% to $17.83 an ounce, up about 2% for the week and was heading for its first weekly gain in three, while platinum <XPT=> remained flat at $937.82.

(Reporting by Asha Sistla and Brijesh Patel in Bengaluru; Editing by Dan Grebler and Grant McCool)