MIDEAST STOCKS-Most Gulf bourses gain on oil

Jan 13 (Reuters) - Most major stock markets in the Gulf rose in early trade on Tuesday, helped by climbing oil prices, while investors assessed the possible impact on the dollar and interest rates of the U.S. administration's threats of a criminal indictment against Federal Reserve Chair Jerome Powell.

Oil prices - a catalyst for the Gulf's financial markets - extended gains as heightened concerns over Iran and potential supply disruptions outweighed the prospect of increased crude supply from Venezuela.

Dubai's main share index .DFMGI gained 0.6%, with top lender Emirates NBD ENBD.DU rising 1%.

In Abu Dhabi, the index .FTFADGI was up 0.3%.

In the U.S., President Donald Trump's administration appears to be on the offensive again against the Federal Reserve, reviving concerns about the central bank's independence and contributing to greater uncertainty over the economic outlook.

Gulf markets often track shifts in U.S. rate expectations, as most regional currencies are pegged to the dollar.

Further fuelling geopolitical worries, Trump said Monday that any country doing business with Iran will be hit with a 25% U.S. tariff, as Washington considers how to respond to Iran's crackdown on major anti-government protests.

Saudi Arabia's benchmark index .TASI was flat in choppy trade. Oil giant Saudi Aramco 2222.SE was up 0.7%.

The Qatari index .QSI gained 0.2%, with Qatar Islamic Bank QISB.QA up 0.7%.