BANGKOK - Thailand's first female prime minister will this week join a long list of Asian women leaders whose power stems from family ties, with analysts saying the trend is a mixed blessing for equality.

Political novice Yingluck Shinawatra went from virtual unknown to election victor in a matter of weeks after her brother, fugitive former leader Thaksin, endorsed her Puea Thai party's candidacy, assuring voters she was his "clone".

Her stellar rise, set to be formally completed this week, mirrors stories from across Asia, with a collection of women whose family names - and often the death of a male predecessor - propelled them to power.

The assassination of a husband saw Sri Lanka's Sirimavo Bandaranaike become the world's first female premier in 1960 and, more than two decades later, thrust Filipino housewife Corazon "Cory" Aquino into the limelight.

In India, Indira Gandhi inherited leadership from her father, Jawaharlal Nehru - a route also taken by Pakistan's Benazir Bhutto and Indonesia's Megawati Sukarnoputri.

Aung San Suu Kyi would have followed in the footsteps of her independence hero father, but Myanmar's junta disregarded her party's 1990 election win.

Analysts believe the phenomenon has much more to do with the prevalence of political dynasties in the region than improvements in gender equality.

Paul Chambers, senior research fellow at Payap University in the Thai city of Chiang Mai, said traditionally Asian women were "not supposed to be political leaders" in the region's "macho", patriarchal culture.

But "under-developed" political parties that enable wealthy families to dominate have created opportunities for women - as a last resort.

"Heredity is important because party leaders prefer to trust their relatives to keep party leadership within the family. Where male party leaders do not have male relatives available, they will turn to daughters," he said.

Bridget Welsh, Associate Professor in Political Science at Singapore Management University, stressed that men - such as Bhutto's husband, current Pakistan leader Asif Ali Zardari - had also come to power this way.

"The fact is that these systems are dominated by elites and men and women both gain power from the elite," she said.

Political dynasties are seen in other parts of the world but Asia is striking for the lack of female leaders who have come to power in any other way.

In Thailand, analysts said Yingluck was boosted by voters attracted to the novelty of her gender, relative youth and good looks.

Welsh said she would ultimately be judged on her performance, adding that once given the opportunity to govern, Asia's female leaders had left a "mixed" legacy.

Yingluck was a respected businesswoman before coming to power in a country that boasts the greatest percentage of women in senior management in the world, according to research by consultancy Grant Thornton earlier this year.

But her election win - under the party slogan of "Thaksin thinks, Puea Thai does" - was seen more as a victory for her brother than a leap forward for feminism in Thailand.

Female political representation lags in the country with women winning just 13 per cent of seats in Thailand's lower house in the last election in 2007, according to figures from the Inter-Parliamentary Union.

The IPU puts the world average at 19.5 per cent, while in Asia it is 18.3 per cent and in the Pacific 12.4 per cent.

Appearances can be an asset for women politicians, such as when India's press was thrown into breathless excitement during a recent visit by Pakistan's glamorous new 34-year-old foreign minister Hina Rabbani Khar.

Mass circulation Hindi newspaper Navbharat Times said India was "sweating over model-like minister", as Khar - whose uncle was once chief minister of Punjab province - had an instant impact on one of the world's most tense bilateral relationships.

Regional neighbours New Zealand and Australia have seen women rise to lead their countries on their own merits.

But even there having having a female leader does not guarantee equality or liberal attitudes.

In Australia, where Julia Gillard is prime minister, a sexism row was sparked in parliament in June after a male senator miaowed at a female senior minister.

Nonetheless things are changing in the region.

In Taiwan, opposition leader Tsai Ing-wen is vying to become the island's first woman president in the January 2012 elections, without having the backing of a familial predecessor.

"Having seen female leaders before them, Asian voters are increasingly likely to accept more and more female politicians. So the future is ripe for a greater female presence in Asian politics," said Chambers.