Shareholders in BP balked Monday at reports it would seek a strategic investor to ward off takeover bids, as the clean-up costs of its massive U.S. oil spill topped $3 billion.

As containment efforts continued in the devastated Gulf of Mexico, where a ruptured well has been spewing crude since April 20, tests on a supertanker adapted to skim large quantities of oily water from the surface were inconclusive because of high seas, ship owner TMT Shipping Offshore said.

Over the weekend, while U.S. Independence Day vacationers largely avoided Gulf of Mexico beaches tarred by the leaking well, media reports said BP was looking for a strategic investor among the sovereign wealth funds of the Middle East and Asia.

Such an investor would help ward off a takeover and raise funds for the liabilities generated by the worst oil spill in U.S. history, the reports said. The spill has been politically disastrous for BP, pitting it against the Obama administration, Gulf communities and a seething American public.

BP shares were up 3.5 percent in London but off earlier intraday peaks on the reports; however some shareholders balked at the idea of a strategic investor.

We don't think a strategic partner is at all necessary, said one top-10 BP shareholder who did not want to be named. We think this is just people trying to panic the company and stampede into doing something to earn huge fees from selling new shares in BP. Shareholders will be saying 'No, thank you' to this and we have communicated this to the company.

Another top-10 investor agreed that BP probably did not need a strategic investor at the moment.

Britain's Sunday Times said BP's advisers were trying to drum up interest among rival oil groups and sovereign wealth funds to take a stake of between 5 and 10 percent in the company at a cost of up to 6 billion pounds ($9.1 billion). BP declined to comment.

One former investment director at a Dubai-based state investment company said it was a predictable move for BP but he doubted the company would find a taker among the oil rich sovereign wealth funds (SWFs) of the Middle East.

A London banker said any SWF involvement might more likely involve the Far East than the Middle East.

Separately, several newspapers reported interest among SWFs in buying some of BP's assets in the Middle East and Asia. BP has said it hopes to raise $10 billion from asset sales this year as part of its plan to fund a $20 billion clean-up fund set up under pressure from U.S. authorities.

Arabic language daily al-Jarida was most specific, saying state-run Kuwait Foreign Petroleum Exploration Co (KUFPEC) is reviewing investing in oil fields in Egypt, Yemen and east Asia.

BP shares have lost more than half their market value since the spill was unleashed on April 20, the result of an explosion on a drilling rig that caused a well to rupture.

Attempts to stop the flow have not worked, with BP pinning hopes on a relief well that should be complete in August.

The stakes could hardly be higher as the disaster is playing havoc with wildlife, fragile coastal ecosystems, fishing communities and a tourist industry seen as especially important during a time of high unemployment.

A WHALE

Some oil is being captured through a pipe, while some is being burned off. BP said it collected or burned 24,955 barrels Sunday but estimates of the total amount flowing vary and go as high as 100,000 barrels a day.

The supertanker dubbed A Whale, which is being tested, is seen as a potential savior of efforts to clean the oil pollution because it can collect 500,000 barrels (21 million gallons) per day of contaminated water.

Tests on the so-called 'super skimmer' conducted just north of the blown out BP well were supposed to be completed on Monday but have been extended because of the weather, said spokesman Bob Grantham.

After an initial 48-hour testing period results remain inconclusive in light of the rough sea state we are encountering, Grantham said.

Skimmer vessels have been out in force -- a fleet of 89 returned through the Biloxi Bay channel Sunday -- but the hurricane season has hampered efforts and high seas were preventing many from operating.

BP said Monday it had so far spent $3.12 billion on the response effort, including $147 million paid out in claims to those affected by the disaster. Plans are being developed for additional containment capacity, it said.

The Sunday Telegraph reported that BP was facing fresh criticism over its approach to safety as it emerged it did not use an industry standard process, known as a safety case, to assess risk at the Deepwater Horizon rig.

A BP spokeswoman confirmed that it did not use the procedure, developed in Britain after the Piper Alpha oil rig explosion in 1988, at any of its U.S. wells because it was not legally required to do so in the United States.

A federal court last week lifted a six-month drilling ban imposed by the Obama administration. A new moratorium now being sought through the courts is expected to be more flexible and could be adjusted to allow drilling in certain subsea fields.

(Additional reporting by Eman Goma in Kuwait; Writing by Ed Stoddard and Andrew Callus; Editing by Alan Elsner).

Egypt United kingdom Dubai Oil Spill