A Mumbai lane, where India's richest person Mukesh Ambani is building a $2-billion home, has joined the league of the world's 10 most expensive streets, but is outranked by over three-times costlier London's Billionaires Row where steel tycoon Lakshmi Mittal owns three houses.

Altamount Road in India's financial capital Mumbai has been named as the 10th costliest in a survey of the world's top 10 most expensive streets in the world, while London's Kensington Palace Gardens has been ranked at the fourth place.

While the tree-lined street in south of Mumbai is a favourite of India's 'very rich,' Kensington Palace Gardens area in West London is popularly known as Billionaires Row. It has been home to Late Princess Diana and NRI-billionaire Mittal owns three houses on this street.

#	Street	Cost per sq mt
1	Avenue Princess Grace, Monaco	$190,000
2	Severn Road, Hong Kong	$121,000
3	Fifth Avenue, New York City	$80,000
4	Kensington Palace Gardens, London	$77,000
5	Avenue Montaigne, Paris	$54,000
6	Ostozhenka, Moscow	$40,000
7	Via Suvretta, St Moritz	$38,000
8	Carolwood Drive, Los Angeles	$30,000
9	Wolseley Road, Sydney	$28,000
10	Altamount Road, Mumbai	$25,000

• A peek into Mukesh Ambani's $2 bn Mumbai home

In the survey conducted by Wealth-Bulletin, a United Kingdom-based online news and analysis provider for global wealth management industry, Avenue Princess Grace in Monaco has been named at the top with a price tag of $190,000 per square metre.

It is followed by Hong Kong's Severn Road with a price of $121,000 per square metre (sq mt) at second and New York City's Fifth Avenue at third place ($80,000 per sq mt).

Kensington Palace Gardens has made to the fourth place with a price tag of $77,000 per sq mt, while the same for the last-ranked Mumbai's Altamount Road is $25,000 per sq mt.

Noting that the Mumbai lane has always been a popular choice for homes of India's very rich, Wealth-Bulletin said that the street was 'catapulted into the ranks of the world's most expensive when India's wealthiest individual Mukesh Ambani unveiled plans last year to build a residential apartment block on the street at a cost of around $2 billion.'

'The extraordinary, 27-floor building, called Antilia, will be as high as a normal 60-floor skyscraper, have elevated gardens and three helicopter pads,' it said, adding that the prices in Antilia were likely to be at least 25,000 per sq mt or even more.

Other streets ranked costlier than Mumbai's Altamount Road in the list include Avenue Montaigne in Paris, ranked fifth at $54,000 per sq mt, Moscow's Ostozhenka (sixth at $40,000 per sq mt), Via Suvretta in St Moritz (seventh at $38,000 per sq mt) and Carolwood Drive in Los Angeles (eighth ranked at $30,000 per sq mt).

The survey revealed that the prices for the top homes in the best locations appear to have decoupled from the gloom and doom being felt in the wider property market.

'The bursting of the housing market bubble is growing louder, causing increasing concern among a widening spectrum of the population, but for the really wealthy the downturn might have little or no impact on the prices they are paying, or selling for homes,' it said.

Noting one needs to be a billionaire, or not far behind, to live in these streets, Wealth-Bulletin said Moscow's Ostozhenka Street and Mumbai's Altamount Road 'would not have even been considered for the list a decade ago, but their inclusion today shows just how important these cities have become for burgeoning billionaire class in India and Russia.'

• A peek into Mukesh Ambani's $2 bn Mumbai home