Based on January 15th closing prices for both Informa and UBM, this represents a 30 percent premium.
In its statement, Informa said its board "sees compelling commercial and strategic rationale for the Proposed Combination, bringing benefits to Customers and Colleagues, while creating significant value for Shareholders, supported by accelerated growth opportunities and significant synergies".
Shares in Informa were down 8.4% at 685.20 pence in early trade, giving it a GBP5.65 billion market capitalisation. Informa has until 13th February 2018 to either announce a firm intention to make an offer for UBM, or announce that it does not intend to. Current Informa Chairman Derek Mapp will become the chairman of the combined group, UBM added.
The combined group would strongly boost Informa's presence in the exhibition sector, making it larger than its largest competitor Relx.
Pearson's slump from a peak of almost £15 in early 2015 has meanwhile seen the stock fall out of the top 10 in Train's funds, but his Lindsell Train fund group remains one of the stock's biggest investors with 5.2% of the shares, according to Reuters.
The proposed deal would create a leading B2B Information Services Group and address an industry trend towards increased operating scaleand industry specialisation.
In a note to clients following the initial discussions statement, analysts at Citigroup said: "We Think an Increased Focus on Events Is Sensible - Increasing Informa's exposure to our preferred area of large-scale Events should be taken well".