Major investors and analysts are backing Australia's largest listed intellectual property firm IPH's $175 million hostile bid to acquire competitor Xenith, in a move designed to block Xenith's proposed $300 million merger with Qantm.

The proposed merger of the sector's two smaller listed players, Xenith and Qantm Intellectual Property, was set for a vote on April 3 but last month IPH moved to acquire a blocking 19.9 per cent stake in Xenith.