Nasdaq Stock Market has said it expects its $4.5 billion deal to acquire Nordic and Baltic stock exchange OMX, through a complex tie-up with Borse Dubai, will close on February 27.

Nasdaq said Borse Dubai had been successful in a tender offer for OMX shares, which paves the way for it to form the Nasdaq OMX Group.

Separately, Borse Dubai said it expected to hold about 97.6 per cent of shares in OMX after exercising options.

'This is the final milestone of the transaction,' said Nasdaq chief executive Robert Greifeld.

Borse Dubai last year teamed up with Nasdaq to buy OMX under a pact in which Dubai gets Nasdaq's stake in the London Stock Exchange Group and a 19.9 per cent stake in the US exchange, although its voting stake will be limited to 5 per cent.

In turn, Nasdaq, the second-largest US equities exchange, will merge with OMX. Nasdaq will also make an investment in Dubai International Financial Exchange.

In total, Nasdaq's cash-and-stock offer for OMX amounts to roughly $4.5bn, broken down as $1.9bn in cash and about 60.6 million shares.

The takeover has already received the green light from the necessary authorities. Based on Nasdaq's $42.24 per share closing price on Thursday, the stock consideration would be worth about $2.6 billion.