(Reuters) - Hedge funds paying upward of $100,000 per year to track the flights of corporate jets were vindicated when Occidental Petroleum Corp announced two deals last week that matched locations the U.S. oil and gas company’s private plane had recently visited.

FILE PHOTO: Visitors view a Gulfstream G3 business jet, produced by Gulfstream Aerospace, at the Farnborough Airshow in Farnborough July 22, 2010. Image has been rotated 180 degrees. REUTERS/Luke MacGregor

Yet Occidental’s example may represent the exception rather than the rule.

Tracking corporate jets often fuels speculation that makes predicting where a company’s next deal may come from harder rather than easier, according to several hedge fund analysts interviewed by Reuters.

“Historically, flight tracking services have not been that useful,” said one hedge fund analyst who asked not to be named because he was not permitted to speak with the media. “But they hit two home runs back-to-back on Occidental, which makes them look pretty good right now.”

Research firm Gordon Haskett Research Advisors wrote a note on April 29 speculating that Warren Buffet’s investment firm, Berkshire Hathaway Inc may be preparing to invest in Occidental, citing data from Quandl, which tracks corporate jet flights and identified Occidental’s plane as visiting Buffett’s hometown of Omaha.

The following day, Berkshire announced a $10 billion cash infusion into Occidental to back its $38 billion cash-and-stock offer for Anadarko Petroleum Corp.

Last week, a flight by Occidental’s jet to Paris preceded an announcement that Occidental planned to sell $8.8 billion worth of Anadarko’s assets in Africa to Total SA.

Occidental did not immediately respond to a request for comment on the correlation between the deals and the routes of its corporate jets.

Flight tracking services have been gaining prominence, partly because they helped some hedge funds foresee Johnson & Johnson’s $30 billion acquisition of drugmaker Actelion in 2017, but their track record before and after this success has been somewhat spotty.

Corporations can evade monitoring by hedge funds by scheduling deal-related meetings in locations where neither the target or acquirer are headquartered or by using jet leasing services like NetJets Inc - the luxury plane unit of Buffett’s Berkshire - rather than flying their own private planes.

And even when hedge funds do dredge up usable data, there is no guarantee that a corporate flight out to a particular city means that the company intends to do a deal there.

“We recently got excited when we saw that a company’s jet was flying out to New York,” one analyst said. “Until we realized that they were holding an investor conference there that week, where we were already scheduled to meet with them.”