India's billionaire Ambani brothers are struggling to rediscover their Midas touch after a year in which they have been battered by investigations and investor scepticism about their businesses.
Mukesh and Anil Ambani took over their father Dhirubhai's conglomerate after his death in 2002 but an acrimonious five-year scrap over the assets forced their mother to intervene and carve up the empire into two.
Elder brother Mukesh heads Reliance Industries, with assets in mostly the energy and petrochemicals sector while Anil created the Anil Dhirubhai Ambani group (ADAG), from its telecom, finance and utilities interests.
Shares in Mukesh's firm hit a two-year low last week and are down 20 percent in 2011 so far, while Anil's flagship Reliance Communication (RCom) shares have more than halved in the last 12 months.
"Once 'Dhiru' shares were in almost every investor's portfolio," said Hemen Kapadia, chief executive of investment advisory firm Chart Pundit, using the nickname brokers gave the Reliance Industries stock under the Ambanis' father.
"But Reliance stocks have lost some of their gloss," he told AFP.
Mukesh's Fortune Global 500 firm has been dragged down mostly by concerns about slowing gas output from its fields off India's east coast, raising valuation worries for other still-to-be-explored assets.
Output from the KG-D6 field has tumbled nearly 17 percent to 50-51 million metric standard cubic metres a day (MMSCMD), from a peak of 60 MMSCMD last year.
The group had been expected to get a major boost from a $7.2-billion deal with British energy giant BP to explore the Indian company's existing and uncharted deepwater oil and gas fields.
But with gas output falling "the potential valuations for Reliance's future oil reserves... is evaporating," said one oil analyst with a Mumbai-based firm, who declined to be named.
Another headache comes as the energy giant finds itself at the centre of controversy after the national auditor claimed that India's oil ministry and regulator favoured Reliance as it developed the KG-D6 field.
Reliance hit back in a letter to the oil ministry this week, saying its reputation was "severely impacted" by the allegations.
Anil, meanwhile, saw ADAG removed from the leading Sensex index on the Bombay Stock Exchange last week, just as he was trying to revive its fortunes.
The group has faced headwinds since April after federal police quizzed the tycoon and other executives as part of a probe into one of India's biggest graft scandals, involving the awarding of telecom licences in 2008.
Three senior executives from Reliance Telecom are on remand in prison facing charges of cheating, forgery and criminal conspiracy in the high-profile case, which is thought to have cost the country billions of dollars.
A cloud hangs over the group, particularly RCom, said Jagannadham Thunuguntla, head of research with SMC Global Securities in New Delhi.
"Perception is weak, due to regulatory and financial concerns," he said.
Anil has for more than a year been trying to find a foreign investor to buy a 26-percent stake in RCom, which would help lower its ballooning debt of $7.18 billion.
RCom, India's second-biggest mobile phone firm, with a 16.5 percent share, has recorded seven straight quarterly falls in profit, even though India is the world's fastest growing mobile phone market, with 827 million subscribers at April-end, a 35 percent jump year-on-year.
Competition is intense and margins are falling.
To add insult to injury, rival conglomerate Tata Group became India's biggest in terms of market capitalisation last week, beating the combined value of the brothers' companies.
The salt-to-steel Tata Group was worth 4.32 trillion rupees ($96 billion) while the combined worth of the two Ambani brothers groups was 3.46 trillion rupees.
Reliance Industries told AFP it did not comment on share prices. ADAG was not available for comment.