Bids can be made for the right to own and operate links for the 1.2GW Hornsea One and 714MW East Anglia One projects off the east coast of England and the 588MW Beatrice site off the north-east coast of Scotland at the end of October.
Ofgem has auctioned off ownership rights to transmission links for 4.6GW of offshore wind farms.
Since launching the regime in 2009, winning bidders have invested £3 billion (€3.4 billion) in the connections, Ofgem added.
It expects the transmission assets in the latest tender round to be worth more than £2 billion, Ofgem stated.
Jonathan Brearley, executive director for systems and networks at Ofgem, added: "Tendering ownership of links to offshore wind farms has already proven to be a successful way of connecting cleaner electricity generation to the networks at a lower cost for consumers.
"It is also a boost for competition as it attracts new players into the energy market."
"Over the next decade we plan to open up high-value onshore grid updates to competition so that we continue to drive down network costs for consumers," said Brearley.
The UK government awarded final investment decision-enabling contract for difference (CfD) subsidies to Ørsted’s Hornsea One and the Beatrice project, being developed by SSE, Copenhagen Infrastructure Partners and China's State Development and Investment Corporation, in April 2014.
It awarded a CfD for ScottishPower Renewables’ East Anglia One the following February in the UK's first competitive tender round.
The first turbine was installed at Beatrice in July, and commissioning is expected next year.
Meanwhile, construction is under way at East Anglia One and at Hornsea One. Both projects are due online in 2020.