(Repeats to additional clients, removes extraneous word from 4th paragraph)
* Underlying Q2 profit $5.6 bln lags $6.0 bln forecast
* Sees weak H2 performance due to maintenance
* CEO promises faster long-term growth
* Oil spill costs rise by $500 mln but charge reduced
* BP second-biggest faller on FTSE 100
By Tom Bergin
LONDON, July 26 (Reuters) - BP Chief Executive Bob Dudley's promise of strong long-term growth failed to convince investors concerned about the company's post oil-spill strategy.
A year after BP, Europe's second-largest oil company by market capitalisation, staunched the massive leak at its Gulf of Mexico well, investors say Dudley has still not set the company on the road to recovery.
On Tuesday he sought to address that concern, saying deals to secure new reserves this year would help drive performance in 2012 and 2013. But some analysts were unimpressed.
"Other companies have clearly re-defined their strategies over the last 12 to 24 months .. ExxonMobil continues to build its shale gas business in the U.S. and Shell (RDSa.L) is focussed on mega gas projects. But what is BP doing?" Dougie Youngson, oil analyst at Arbuthnot, said in an email to clients.
BP shares were down 2.6 percent at 0920 GMT, the second-biggest faller on the FTSE 100 index of blue-chip stocks. The STOXX Europe 600 Oil and Gas index was down 0.8 percent.
Investors are frustrated at the share price which has failed to recover materially in the past nine months despite some progress in oil spill lawsuits and indications the final cost to the company will be less than many had feared.
Dudley told shareholders: "We are committed to seeing the true value of the business more strongly reflected in our share price".
Some analysts, bankers and investors are beginning to ask whether the best way for BP to address its valuation discount is to break itself up.
U.S. rivals ConocoPhillips , Marathon Oil and Murphy Oil have followed strategies of spinning off their oil refining and fuel retail units.
BP has rejected suggestions it should follow this route but said on Tuesday it was making progress in plans to sell its Texas City and Carson, California refineries.
BP's underlying second-quarter results fell short of analysts' forecasts and benefited less than rivals such as Exxon Mobil and Royal Dutch Shell Plc (RDSa.L) are expected to from a 50 percent rise in crude prices from a year ago.
Excluding one-offs, the replacement cost net income was up 13 percent to $5.61 billion, below an average forecast of $6.02 billion, from a Reuters poll of 12 analysts.
Rivals Exxon and Shell are both expected to post a 50 percent rise in underlying net income.
"For the Bulls on BP there is little in today's results to get excited about," analysts at Bernstein said in a research note.
The London-based company said maintenance work in the North Sea and Angola and continued outages in the Gulf of Mexico had weighed on results in the quarter and would continue to impact performance in the second half of the year.
BP said oil and gas production fell by 11 percent in the quarter to 3.43 million barrels of oil equivalent per day, after the company sold fields to pay for the spill and due to maintenance work.
The company again increased its estimate for the cost of dealing with the spill, adding around $500 million to the bill, although contributions of $1.1. billion from partners allowed the total charge taken by BP to be reduced.
Replacement cost net income was $5.31 billion, compared with a loss of $16.97 billion in the same period last year that included the cost of tackling its massive Gulf of Mexico oil spill. (Editing by Erica Billingham)