(The Wall Street Journal) -- A day after snapping up a 9.98% stake in Swedish stock exchange operator OMX, a Qatari investment firm started preparing for a further increase in its stake, according to people close to the matter.

In the latest maneuver of an emerging battle between Qatar and Gulf rival Dubai for a place in the global financial-exchange business, Qatar Investment Authority Friday contacted large OMX shareholders and arranged meetings with important institutional investors, people close to the matter said.