People visit the stand of Qihoo 360 during the 2015 Appliance and Electronics World Expo in Shanghai, Mar 13, 2015.[Photo/IC]

A $1.24 billion agreed takeover of Norwegian online browser and advertising company Opera Software by a Chinese consortium of internet firms has failed, Opera said on Monday, after warning last week the deal had yet to win regulatory approval.

As an alternative, the consortium, which includes search and security business Qihoo 360 Technology Co and Beijing Kunlun Tech Co, a distributor of online and mobile games, will take over certain parts of Opera's consumer business for $600 million, Opera said in a statement.

The Norwegian firm did not specify the reasons on Monday for the scuttling of the deal other than to say that conditions to close the public offer were not met.

The deal had needed the approval of Chinese and US authorities, but last week Opera warned that regulatory approval had yet to be received, without specifying whether approval from China, the United States, or both, was lacking.