NEW YORK (

TheStreet

) -- Oil drilling company

Nabors Industries

(NBR) - Get Report

said that the

Securities and Exchange Commission

has opened an investigation into executive perks offered by the company, namely use of a corporate jet for personal travel.

A regulatory filing by Nabors on Wednesday revealed the SEC investigation.

It's not a surprise that Nabors is facing heat over executive perks, though the formal SEC investigation ups the ante. Two weeks ago, Nabors revealed in a filing that its outgoing CEO Eugene Isenberg would receive a $100 million severance payment for stepping out of the CEO role, while remaining on as chairman of the company. It was just the latest in a long history of

excessive executive compensation

at Nabors, as

TheStreet

detailed on Nov. 4. Even analysts on Wall Street who support the stock and as a rule shy away from ever confronting management directly had trouble swallowing Isenberg's parting gift.

The use of corporate jets for personal travel by executives has been outlined in previous filings from the oil company, and was the focus of a

Wall Street Journal

piece on corporate jet use written in June.

Nabors' jets made frequent stops in Palm Beach, Fla., and Martha's Vineyard, Mass., both spots where Nabors Chairman Eugene Isenberg has residences, according to

The Wall Street Journal

, which estimated the flights cost about $704,000. Nabors provided no such estimate.

Companies generally must disclose on an annual basis the cost of personal use of corporate planes by officers, if it exceeds either $25,000 or 10% of the cost of all perks. The

Journal

noted in a follow-up to its original report on the perks, published Thursday, that Isenberg's employment contract with the company, filed with the SEC in April 2009, entitles him to establish company-subsidized offices at or near his principal residence in Palm Beach "and/or at any other residence maintained by him." The contract also entitles him to perform his duties "from offices in or near his places of residence."

The $100 million parting payday for Isenberg is downright paltry compared with the previous versions of the same "contingent liability" clause in his contract too, which ran as high as $329 million before it was reduced to $100 million. It is an example, like the personal jet use, of the frustration that has always been associated with what critics call a Nabors management that isn't even tone-deaf, but simply couldn't care less about criticism of its compensation and perks policy.

As analyst Phil Weiss of Argus Research told

TheStreet

when Isenberg's $100 million "retirement" paycheck was revealed, "I haven't had a buy on Nabors in a long time and would be hesitant to put one on because of concerns about the way management runs the company. Any time the stock seems cheap I say, 'Yeah, but it's still run by Isenberg.' "

Nabors has not performed well vs. peers either in recent years. In the past five years, Nabors shares have declined by more than 38%, while close peer

Helmerich & Payne

(HP) - Get Report

has increased shareholder value by 116%. The

S&P 500

is down 10% in the same five-year period. In the past year, the S&P 500 is up 1%. Nabors? Down 11%. Helmerich & Payne, meanwhile, has gained 18%.

"Isenberg has a tendency to overpromise and underdeliver," said Argus Research's Weiss. "The stock has underperformed and he has been egregiously overpaid." And apparently, overflown too, at the expense of Nabors shareholders.

Nabors shares were flat on Thursday.

-- Written by Eric Rosenbaum from New York.

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>>5 Dumbest Things on Wall Street - Nov. 4

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