Dubai's ruler has promoted Essa Kazim to become chairman of bourse operator Dubai Financial Market (DFM), one month after appointing him as the new governor of the emirate's tax-free financial zone, a bourse statement said on Wednesday.

Kazim is currently chief executive of DFM. The statement did not clarify whether a new chief executive would be named to replace him in that post.

The latest appointment comes amid speculation in the market that DFM may merge with the Abu Dhabi Securities Exchange in a state-backed deal that could energise financial markets in the UAE. Sources familiar with the proposal told Reuters this month that Abu Dhabi and Dubai had hired banks to advise them on the issue.

Kazim replaces veteran banker Abduljalil Yousuf Darwish as chairman of DFM, the only listed bourse operator in the Gulf. DFM is one of the best-performing exchanges globally this year; the benchmark market index is up 80 percent year-to-date while DFM's own shares have risen 127 percent.

Kazim will replace current governor Abdullah Mohammed Saleh as head of the Dubai International Financial Centre (DIFC) on January 1. He is also chief executive of Borse Dubai, the holding company for DFM and the emirate's other stock market, Nasdaq Dubai. -Reuters