The tycoon behind Zoopla and uSwitch has made a secret takeover bid for Gocompare.com valuing the rival price comparison site at more than £400m.
Sky News has learnt that ZPG, which is headed by the entrepreneur Alex Chesterman, approached the board of Gocompare in recent days to propose buying the company for a price thought to be in the region of 110p-a-share.
The proposal is said to have been rejected by Gocompare's board, which is chaired by Sir Peter Wood, one of the most successful figures in British insurance.
At 110p, the offer represented a roughly 20% premium to the level at which Gocompare shares were trading on Tuesday afternoon, although they were trading higher than the offer price as recently as a month ago.
The shares have already traded up by more than 40% over the last year, with investors apparently enthused by its evolution into a broader technology company and backing of other start-ups such as Mortgage Gym.
Sir Peter also heads Esure, the owner of Sheila's Wheels, which has also been the subject of takeover speculation in recent months.
He recently sold a 5% stake in Gocompare at a discount of just under 10% to the price proposed by ZPG.
Gocompare – best-known for the fictional operatic star of its advertising campaigns, Gio Compario – was demerged to become a separately listed company a year ago.
It was unclear on Tuesday whether ZPG planned to return with a fresh offer for Gocompare.
If it does, it would signal Mr Chesterman's efforts to continue leading the consolidation of the burgeoning price comparison sector.
ZPG owns property sites such as PrimeLocation and Zoopla, the home services switching specialist uSwitch and recently acquired Money.co.uk, the financial services comparison site.
It now has a market capitalisation of about £1.5bn, making it well over three times the size of its target.
Deutsche Bank is understood to be advising Gocompare on the approach from ZPG, which is being advised by Credit Suisse and Jefferies.
A spokesman for Gocompare.com declined to comment, while ZPG could not be reached.
Competition regulators recently gave the price comparison market a relatively clean bill of health, although they have opened a further probe into Comparethemarket over the way it has set up contracts with insurers.
The site's owner, BGL, has been considering a London stock market listing for some time.