Costas is co-head of Gilbert + Tobin’s Corporate Advisory group and is a member of Gilbert + Tobin’s Board of partners.

Costas has significant experience in Mergers and Acquisitions, Takeovers, Corporate and Securities Law, Capital markets, Directors Duties and Corporate Governance and the Listing Rules.

He is widely recognised as one of Australia's leading strategic M&A and securities lawyers. He is known for his in-depth industry knowledge and experience in advising on some of Australia’s most prominent, novel and complex deals.

Costas has a Bachelor of Economics from the University of Sydney, a Bachelor of Laws (Honours) from the University of Sydney and holds a Graduate Diploma in Applied Finance from the Securities Institute of Australia.  He is an adjunct member of the Faculty of Law at the University of Sydney where he lectures on the Takeovers Panel in the Masters of Laws.

Costa's experience includes advising:

  • MoneyMe on its initial public offering.
  • Ruralco on the $1.1 billion (enterprise value) take private by Nutrien Ltd.
  • Adamantem Capital on its acquisition of ASX-listed Legend Corporation Limited by way of scheme of arrangement.  
  • Shaw and Partners on the sale of 51 per cent of its shares to SIX Swiss Exchange-listed EFG International and associated shareholder arrangements.
  • GrainCorp on its $3.3 billion approach from Long-Term Asset Partners Pty Ltd.
  • Investa Property Group on the $3.4 billion contested acquisition (by trust scheme) of Investa Office Fund between Oxford Properties (OMERS) and Blackstone.  
  • Yancoal Australia on its dual primary listing on the Hong Kong Stock Exchange and the associated IPO of its shares to raise HK$1.605 billion.
  • The Stars Group Inc. on its acquisition of 80% of CrownBet, and CrownBet’s acquisition of William Hill.
  • Sonic Healthcare on its $750 million acquisition of Aurora Diagnostics and its $600 million capital raising to part fund that acquisition.
  • Whitehaven Coal on its $350 million acquisition of the Winchester South coal development project from Rio Tinto.
  • AMA Group on its proposed demerger of its automotive component, accessory, and procurement business, and the proposed take private of AMA Group (post demerger) by Blackstone for an enterprise value of $508 million.
  • Yancoal Australia’s Independent Board Committee on the US$3.4 billion acquisition of Coal & Allied Industries from Rio Tinto and the associated US$2.5 billion entitlement offer and placement to fund that acquisition, and associated Takeovers Panel proceedings.
  • Investa Property Group on the purchase of Cromwell's stake in IOF, and the proposed sale of its investment management platform to IOF.
  • Iron Mountain on its successful and innovatively designed $3.8 billion scrip acquisition of Recall Holdings by scheme of arrangement, and its associated dual listing on ASX.
  • Vocus Communications on its $3 billion merger of equals with M2 Group by way of scheme of arrangement.
  • CIMIC on its successful $256 million unsolicited takeover bid for Sedgman Limited, including associated Takeovers Panel proceedings.
  • Anchorage Capital on its successful $212 million contested acquisition of Affinity Education Limited by scheme of arrangement, and associated Takeovers Panel proceedings.
  • TPG Telecom on its contested $1.57 billion acquisition of iiNet Limited by scheme of arrangement.
  • Yancoal Australia Independent Board Committee on its US$2.3 billion pro rata subordinated capital notes offer and balance sheet recapitalisation, and associated Takeovers Panel proceedings.
  • Vocus Communications on its novel and Court contested $1.2 billion merger of equals with Amcom Limited, the first Australian merger scheme to succeed in the face of a 20% blocking stake.

Costas has been recognised for his work in Commercial Law, Corporate Law, Equity Capital Markets Law, Mergers & Acquisitions Law and Telecommunications Law.

Best Lawyers Australia 2022

Costas is ranked in the Corporate/M&A category.

Chambers Asia-Pacific 2021

Costas was recognised in the Corporate/M&A category.


Costas is ranked as a leading individual in the Corporate/M&A category.


Costas is recognised as Highly Regarded in the Capital Markets: Equity and Corporate/M&A categories.

IFLR1000 2021

Costas was named 'Lawyer of the Year (Sydney)' for Commercial Law in 2019 and ‘Lawyer of the Year (Sydney)’ for Corporate Law in 2019, 2016, 2015 and 2014.


Costas is praised for being "very strategic and tactical" and for providing "some very clever ideas on a very challenging transaction", and that Costas is applauded by clients for his "standout commercial judgement."

Chambers Asia Pacific

Chambers Global says peers note the strong technical skills of Costas who is a "responsive and skilled M&A practitioner with strong technical skills and excellent commercial judgement", and that Costas has "an amazing legal mind, providing an outstanding mix of technical skill and commercial judgement." They also appreciate that he is "down to earth - his ego doesn't get in the way.”

Chambers Global