The authority, Finansinpektionen or FI, said it had determined that Nasdaq “meets the criteria required by law” to acquire OMX.
Nasdaq and the United Arab Emirates group Borse Dubai on September 20 launched a joint takeover offer for OMX. Ownwership of OMX is ultimately to be transferred to Nasdaq under a complex agreement that will give Borse Dubai a stake in Nasdaq.
OMX operates exchanges in Copenhagen, Stockholm, Helsinki, Reykjavik, Riga, Tallinn and Vilnius.
Borse Dubai and Nasdaq said Wednesday they had sweetened their bid for OMX and had secured 47.6 percent of its shares.
Major OMX shareholders Investor and Nordea agreed to sell their stakes for 265 kronor per share ($40.60) in cash, Borse Dubai said in a joint statement with Nasdaq, higher than the initial offer of 230 kronor.
The new offer values OMX at 32 billion kronor, or $4.9 billion.