Cairn has already taken out $491 million until 2005, against a recoverable cost of $555 million. The recoverable cost within this year would exceed $600 million. This cost is nearly three times that of a single on-shore gas field developed by other foreign oil companies.

All the while, the financially weak Petrobangla last year swallowed an audit objection of $239 million against the Sangu investment. These objections were raised over the years for either unauthorised expenditure or over-expenditure. Allegations are made against two Petrobangla high officials that they undermined national interest in clearing the objections. The clearance of this audit objection, however, remains to be approved by the Petrobangla board.

A nearly similar picture is seen with Chevron's Jalalabad and Moulavibazar gas fields where the US company has been allowed to take out $275 million against a total investment of $474 million, along with a total audit objection of $ 222 million. This entire audit objection has remained unresolved.

A financial comparison of the two operators shows that the country's first offshore gas field Sangu has become a massive foreign investment drainage system for the country. Such high investment is not producing enough gas compared to Jalalabad and Moulavibazar.

Offshore fields are supposed to be costlier, but the investment figures of Sangu versus Jalalabad and Moulavibazar fields are shockingly disproportionate in terms of performance.

While Cairn's $555 million Sangu field is now producing around 90 million cubic feet gas per day (mmcfd), Chevron's $474 million Jalalabad and Moulavibazar gas fields are producing 340 mmcfd.

Cairn sources said the audit objection issue has been resolved through a six-member committee. This committee formed in 2005 was comprised of two members from Petrobangla and four from Cairn and its financial partner Haliburton.

"This committee worked for 14 months and held at least 30 meetings. At these meetings, Cairn produced original documents on procurements to help Petrobangla decide on the validity of the audit objections. Finally, it was resolved. This decision is awaiting board approval," said a Cairn official requesting anonymity.

But payments were made when the audit objections were yet to be resolved.

A senior Petrobangla official explaining why Cairn has been allowed to take out investment which fell under the purview of audit objection, said, "We have allowed so with the condition that this payment is provisional. When the audit objections will be resolved, Cairn will pay back the money if it is found to have taken excess."

This system is followed in dealing with Chevron's investment too.

Last year, a legal adviser to Petrobangla dealing with audit objections raised questions why it was giving such a provisional payment and under which clause of the agreement with Cairn.

"He said that the agreement does not demand such payments. Petrobangla should not pay this money unless the dispute is resolved," said a source quoting the legal adviser's opinion.

As Petrobangla's monitoring and financial scrutiny strength has diminished in the last six-seven years, it is now unable to take the right financial decisions, he added.

"It's been many years since the Petrobangla saw a professional financial personnel at the position of director finance. It's ironic that the government never bothered about placing a highly competent person in this chair even though Petrobangla is fetching the government around Tk 3,000 crore a year and overseeing assets worth billions of dollars," the source pointed out.

"It's not Sangu's financial matter that's in a mess. The whole financial discipline related to gas production under PSCs (production sharing contracts) is now in a mess and demands attention of the government," he added.

The first round unsolicited oil and gas bid of the early nineties put the Chevron (previously Occidental) deal as the winning deal.

Since signing of the PSCs on block-15 and 16 in 1994 and 95, Cairn invested a total of $664.86 million by 2005. Of this, $108.91 million invested on block-15 is non-recoverable as Cairn could not hit any single gas or oil field in that block.

In block-16, however, Cairn's investment continues to shoot up stunningly every year. The Sangu field remains Cairn's lone success till date.

Since the May 5, 1994 PSC was signed, Cairn invested half a million dollars in 1994, $15 million in 1995, $26 million in 1996, $165 million in 1997, $102 million in 1998, $34 million in 1999, $55 million in 2000, $22 million in 2001, no investment in 2002, $31 million in 2003, $46 million in 2004 and $57 million in 2005.

In contrast, Chevron (originally Occidental, then Unocal) invested $474 million between 1995 and 2005 in three blocks, block-12, 13 and 14, under two PSCs.

Unlike Cairn, Chevron's deal included an already discovered gas field, Jalalabad. Apart from that, Chevron discovered and developed Moulavibazar and Jalalabad gas fields -- all within $474 million -- and is supplying more than 340 mmcfd gas.

Cairn started recovering its investment for Sangu from 1998, with $11.95 million in the first year, then $38.86 million in 99, $71.71 million in 2000, $80.74 million in 2001, $90.44 million in 2002, $81.7 million in 2003, $35.18 million in 2004 and $80.75 million 2005.

Chevron started recovering investment for Jalalabad from 1999 with $21.4 million in the first year, followed by $39 million in 2000, $45 million in 2001, $51.89 million in 2002, $18.86 million in 2003, $9.25 million in 2004 and $18.7 million in 2005. It invested $205 million and has recovered it entirely -- allowing Petrobangla's gas share to increase to the maximum level.

Chevron also recovered another $70.93 million from Moulavibazar where it has invested $81.36 million till 2005.

Official documents show that in dealing with Cairn, Petrobangla made its biggest audit objection in 1998 worth of $106 million. Cairn has accepted the objection and resolved the $105 million claim. Such status contradicts with the last year's committee decision to lift the audit objections.