U.S. stock market Nasdaq said on Friday that it remained committed to its plan to acquire Nordic exchange OMX and urged shareholders to support its bid after a $4 billion rival offer emerged from Borse Dubai.

Nasdaq, which had earlier offered about $3.7 billion for OMX, said shareholders should support its offer for several reasons, including the opportunity to own a 28 percent stake in the combined company. It also said that under a merger, the two exchanges can cut costs by at least $150 million a year on a pretax basis.

Nasdaq said it remained in close dialogue with the management team and board of directors at OMX.

(Reporting by Lilla Zuill)