The United Arab Emirates government would favour a merger of the main Abu Dhabi and Dubai bourses, but the decision is up to the exchanges themselves, economy minister Sultan bin Saeed al-Mansouri said on Wednesday.

He was speaking at a session of the Federal National Council, an advisory body to the government, where some members asked the government to work to facilitate a merger and to introduce a timeline for it to take place.

A possible merger of the Abu Dhabi Securities Exchange with the Dubai Financial Market has been discussed on and off for years, and at one stage, investment banks were hired to advise on a tie-up.

But sources familiar with the matter told Reuters last year the idea had been shelved for the foreseeable future as terms for the politically sensitive move could not be agreed. For one thing, wild swings in stock prices over the past couple of years have made it difficult to value assets.

"If at this stage, we as a regulator - if there is a proposition to merge the two markets, we are with it," Mansouri said. "And, if not, we understand."

He also said: "We hope there is one market because as a regulator it would be easier to supervise."

A merger might energise financial markets in the UAE, making it easier for investors to operate across the markets, stimulating trade and attracting more foreign investment.

The Abu Dhabi exchange is fully owned by the Abu Dhabi government, while the Dubai Financial Market is 79.63 percent owned by Borse Dubai, a subsidiary of sovereign fund Investment Corporation of Dubai.