Costas is head of Gilbert + Tobin’s Corporate Advisory group.

    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, and is known for his in-depth industry knowledge and experience in advising on some of Australia’s most prominent, novel and complex deals.

    Costas is an adjunct member of the Faculty of Law at the University of Sydney where he lectures on Schemes of Arrangements and the Takeovers Panel in the Masters of Laws course of Takeovers and Reconstructions.  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.  Costas is also a member of Gilbert + Tobin’s Board of partners.

    Costas’ experience includes advising:

    • APA Group on its $773 million acquisition of the Basslink interconnector pipeline, by acquiring the Basslink group’s secured bank debt and subsequently the Basslink group from the appointed administrators and receivers.
    • Macquarie Asset Management and its co-investors on the $3.58 billion sale of Axicom.
    • CIMIC on its response to HOCHTIEF Australia’s unsolicited takeover bid valuing CIMIC at $6.85 billion.
    • Virtus Health on its response to the extensive and hard fought contest for control labelled “the M&A battle of the year” by the Australian Financial Review involving a proposed scheme of arrangement and simultaneous takeover bid by CapVest, and unsolicited but ultimately recommended takeover bid by BGH Capital, and associated Takeovers Panel proceedings.
    • Yancoal Australia on its response to the unsolicited take private proposal from Yankuang Energy valuing Yancoal at $7 billion. 
    • Anchorage Capital Group on Allegro’s takeover of Slater &Gordon.
    • MoneyMe on its $460 million scrip based merger with SocietyOne. 
    • Orcon on its $1.7 billion merger with 2degrees to create the third largest telco in New Zealand.
    • SiteMinder Limited on its IPO and ASX listing, and pre-IPO capital rounds and sell downs.
    • Macquarie Infrastructure and Real Assets (MIRA) on its $2.4 billion acquisition of Bingo Industries Limited by scheme of arrangement.
    • MIRA and Aware Super on their $3.5 billion acquisition of Vocus Group Limited by scheme of arrangement.
    • Agnico Eagle Mines Limited on its $11 billion scrip merger with Kirkland Lake Gold Ltd.
    • SG Fleet on its acquisition of LeasePlan ANZ (with an enterprise value of $1.5 billion) for a combination of cash and SG Fleet scrip, and its related ANREO to part fund the acquisition. 
    • ARA on its $5.2 billion acquisition by ESR and related downstream takeover acquisition issues in relation to Cromwell Property Group.
    • Cashrewards Limited on its response to 1835i’s (ANZ's) off market takeover.
    • Rubicon Water Limited on its IPO and ASX listing.
    • Arrovest in connection with the recapitalisation of Freedom Foods comprising a $265 million convertible note capital raising and a restructure of debt facilities. 
    • ARA Group on its unsolicited proportional takeover bid for the $2.3 billion Cromwell Property Group.
    • MoneyMe on its IPO and ASX listing.
    • Ruralco on its $470 million acquisition by Nutrien Ltd by scheme of arrangement.
    • Adamantem Capital on its acquisition of ASX-listed Legend Corporation Limited by way of scheme of arrangement. 
    • GrainCorp on its $3.3 billion approach from Long-Term Asset Partners.
    • 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 on its $6 billion merger with Flutter Entertainment, to create the world’s biggest online gaming group (following earlier working on its acquisition 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.
    • 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 is recognised as a Leading Individual in Corporate and M&A.

    The Legal 500 Asia-Pacific 2024

    Costas is ranked Band 1 in Corporate and M&A

    The Legal 500 Asia-Pacific 2024

    Costas was recognised in the areas of Commercial Law, Corporate/Governance Practice, Corporate Law, Equity Capital Markets Law, Mergers and Acquisitions Law, Private Equity Law, Telecommunications Law.


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

    Chambers Asia-Pacific 2023

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


    Costas has been recognised for his work in Mergers & Acquisitions Law, Corporate Law and Equity Capital Markets Law (among other categories) for over 10 years.

    Best Lawyers Australia 2022

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

    IFLR1000 2022

    "A truly exceptional corporate lawyer" who ensures that his clients' "strategically important and high-value transactions are in the right hands"

     “An excellent practitioner and a good person" who possesses “incredible experience, sound judgement, responsiveness, commercial awareness, and ability to communicate and explain complex issues to the board and management."


    “Extremely good to deal with. Always has sound responses, is pragmatic, low on ego, commercial, and easy to talk with.”

    The Legal 500 Asia-Pacific 2023

    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

    “He is an exceptional operator. He is brilliant at distilling and explaining complex legal scenarios for board members and executives. He is highly commercial, pragmatic and possesses deep technical skills.”

    IFLR1000 2021