The Swedish Financial Supervisory Authority said Thursday it has sent more questions to Borse Dubai regarding its share and option purchase in Nordic stock exchange operator OMX last week.
The Swedish regulator is investigating whether Borse Dubai's book-building process in OMX -- which has already agreed to a takeover offer by the U.S.-based Nasdaq Stock Market -- constituted a public takeover bid for the company.
Borse Dubai said Tuesday that its announcement that it could raise its stake in OMX up to 27.4% should not be seen as a takeover offer.
However, Borse Dubai said it wants to acquire "a large stake in OMX" and intends to pursue discussions with the company's board and its largest shareholders on future cooperation.
The Swedish Financial Supervisory Authority said Thursday it had asked Borse Dubai to provide further details on the option contracts it has entered into with selected investors and to detail at what time its first press release on the deal was made public.
The regulator also asked Borse Dubai to provide a copy of one of the option contracts.
Borse Dubai has until early Monday to provide the information.
The investigation comes after government-owned Borse Dubai said last Thursday that it had bought a 4.9% stake in OMX for 230 kronor, about 25 euros or $34, a share, and had entered into option agreements to purchase another 22.5% at the same price.
The move was seen as a potential challenge to Nasdaq Stock Market's $3.7 billion cash-and-share agreement of May 25 to buy OMX.