Wall Street Journal: BP PLC (BP) said Thursday that it sees no justification for the collapse in its share price, even as it admitted the cost of the Gulf of Mexico oil spill has risen to $1.43 billion and U.S. politicians pushed for the company to assume even greater liabilities. BP shares opened down 11% in London Thursday, which took the company's value to a 13-year low, following a fall of 16% Wednesday in U.S. trading.