The Dubai stock market index ended with its biggest-one day gain ever, jumping 10.53 percent, as a government vow to guarantee deposits and interbank lending, coupled with rising overseas markets, enticed traders back into the market.

The main index soared 10.53 percent to end at 3,343.56, supported by banks and real estate stocks. Emaar Properties rose 15.01 percent while Ajman Bank and Dubai Islamic Bank both gained more than 14 percent.

In Abu Dhabi, the index closed up 6.92 percent, buoyed by Abu Dhabi Commercial Bank and Abu Dhabi Islamic Bank, both up more than 9 percent.

Qatar's bourse surged after the country's sovereign wealth fund unveiled plans to buy 10-20 percent of listed banks' capital, sending bank stocks careening higher.

The Qatar main index ended up 8.45 percent at 7,624.09 with Qatar Commercial Bank up 9.2 percent.

Analysts were hesitant to claim this is the end of weeks-long declines on regional bourses. 'It's weak signals still,' said Nadine Wehbe, senior market analyst at Orion broker.

The Omani bourse ended higher, tracking an upswing in global markets while a rally in regional markets lends further support.

The index rose 5.18 percent to close at 7,121.32 as Ahli Bank jumped 9.84 percent while National Bank of Oman closed up 9.9 percent.

'I think it's a turnaround,' said a trader about the rebound in reginal markets. 'We've been looking for something dramatic, the market has already fallen a huge amount. I think it's a big deal.'

Saudi index opened higher, amid upbeat regional sentiment, as investors showed renewed confidence in market after fresh government measures in the UAE and Qatar. The main index  rose 5.12 percent led by banks.

Hollandi Bank was up 6.15 percent while SABB Bank gained 8.25 percent. Abdulhamid Al-Amri, a member of the Saudi Economic Association,  semi-official think tank, also credited a rare Saudi repo rate cut for the gains.

'Sama's moves restored investors' confidence that authorities are finally doing something and the right thing to help the bourse,' he said.

He added that the raft of IPOs approved by the bourse regulator over the past 18 months, which coincided with steps by Sama that have tightened liquidity, had been 'choking the market'.

'Nobody knows if this is the beginning or the end,' said Amro Motasim, chief trader at Ahli Bank in Doha. 'It may (run for) one or two days. Nothing has changed. The situation is bad, you've foreign institutions that are still selling. This might end up being a dead cat bounce.' - Reuters