Dubai International Financial Centre (DIFC), the owner of the Dubai stock exchange, is mulling a rival bid to Nasdaq's agreed $3.7 billion takeover of Nordic markets owner OMX,the Sunday Times of London reported.
The paper said, without naming sources, Dubai government-owned DIFC had appointed HSBC to advise it on the potential counterbid.
DIFC Governor Omar bin Suleiman told Reuters on Thursday it was not considering making a bid for OMX.
DIFC could not be reached for comment on Sunday.
OMX spokesman Niclas Lilja declined to comment on whether OMX had been in talks with DIFC or whether it had been approached by the Dubai group.
He noted the deal between OMX and Nasdaq , announced on Friday, had wide support.
"This was agreed by the boards of both companies and by large shareholders," he said.
The deal between Nasdaq and OMX brings together the largest electronic stock market in the United States and the owner of the share markets in Stockholm, Helsinki, Copenhagen, Iceland and the Baltic states.
It includes OMX's market technology business, which accounts for over a third of its annual turnover.
Nasdaq is already the second largest share market in the world behind the NYSE, last year trading shares worth $11.8 trillion versus the NYSE's $21.8 trillion, according to World Federation of Exchanges data.
OMX ranks 11th with a market turnover of $1.3 trillion.