Australian prime minister Julia Gillard praised Baroness Thatcher for her "strength of conviction".
She said: "Her service as the first female prime minister of the United Kingdom was a history-making achievement.
"Her strength of conviction was recognised by her closest supporters and her strongest opponents.
"I extend my sincere condolences and those of my fellow Australians to her family and friends."
Former Australian prime minister Kevin Rudd ruled out a challenge to incumbent Julia Gillard in a vote for the leadership of the Labor Party.
Julia Gillard will remain as Prime Minister after she stood unopposed in a leadership ballot.
Rudd, who was rolled by Gillard in 2010, said he gave his word a year ago that he would not challenge again, and that he would only return to the leadership if drafted with the overwhelming support of the Labor Party. But he said those circumstances did not exist at present.
Julia Gillard has committed five million Australian dollars to support services for affected families and to help biological families reunite.
The Prime Minister apologised for the police after it was recommended a year ago by a senate committee that investigated the impacts of the now-discredited policies.
Watch: PM apologises to Australian mothers for 'forced adoptions'
Unwed mothers were pressured, deceived and threatened into giving up their babies from World War II until the early 1970s so they could be adopted by married couples, which was perceived to be in the children's best interests, the senate committee report found.
Western Australia was the first of five state and territory governments to apologise for forced adoption. Australia has eight such governments.
Roman Catholic hospitals in Australia apologised in 2011 for forcing unmarried mothers to give up babies for adoption and urged state governments to accept financial responsibility.
The Australian Prime Minister Julia Gillard has delivered an historic national apology to the thousands of unmarried mothers, who were forced by government policies to give up their babies for adoption over several decades.
Read: Gillard pledges $5 million to support 'forced adoption' families
More than 800 people, many of them in tears, heard the apology in the Great Hall of Parliament House as Ms Gillard apologised for the 'forced adoptions and responded with a standing ovation.
In her first major political speech of 2013, Australian Prime Minister Julia Gillard, has called an election for September 14th.
Usually lasting a month, the Australian election campaign could now become one of the longest in Australian political history.
Ms Gillard said that she would ask Governor-General Quentin Bryce to order parliament be dissolved on August 12.
Gillard's minority holds a one seat majority, with support from independents and the Greens.
Polls suggest her government would be out of office if the elections were held now.
Australian Prime Minister Julia Gillard stumbled and fell as a shoe got stuck in soft grass on a visit to the Gandhi Memorial in New Delhi.
Read the full storyThe Australian Prime Minister Julia Gillard lights a beacon in celebration of the Queen's Diamond Jubilee.
She said: "These beacons glowing around the world symbolise one family across a wide world, the family of the Commonwealth nations, rich in their diversity but united now in admiration for the unstinting service of the Queen."
