Alice Spizzo, David Tindale and David Speiser have been named as directors of the firm.
Ms Spizzo, who has 25 years' experience in the planning and property sector, joined Landerer & Co one year ago from Lander & Rogers.
Commercial property lawyer Mr Tindale joined the firm in March last year, having previously held senior positions at King & Wood Mallesons and Ryan Lawyers.
Meanwhile, Mr Speiser joined the firm in June last year from Arnold Bloch Leibler and has 13 years' experience in transactions, corporate advisory and litigation.
The firm also appointed two new special counsel, litigator Bill Fragos and commercial lawyer Payal Mahindroo.
Mr Fragos is a member of the Law Council’s competition and consumer law committee and a former adviser to the South Australian commissioner for consumer affairs and the South Australian attorney-general.
Ms Mahindroo has worked for a variety of firms, including Ashurst and Clayton Utz, specialising in banking and finance.
Planning and environment lawyer Emma Fleming has also been appointed as a senior associate.
Landerer & Co now has 12 directors and 25 lawyers in its Sydney practice.