Delays could mean French oil giant Total SA's (TOT) capital expenditure will fall short of $18 billion this year, Chief Executive Christophe de Margerie said Thursday.

While Total is maintaining a capex program of $18 billion for 2009, de Margerie said he doesn't know if the company will spend the full amount, adding that there might be delays.

"It's a huge amount $18 billion," de Margerie told delegates at an oil conference, adding: "Will it be this at the end of the year? I don't know."

"I have a feeling that, for different reasons, there might be delays," he said.

De Margerie later expanded on the comments, telling reporters on the sidelines of the conference that financial constraints would not be the cause of any delay.

"We notice simply that in the partnerships we are in, there are, for all sorts of reasons, with other partners, things that mean projects have a tendency to be delayed," he said. Delays wouldn't be caused or wanted by Total, he said.

"We have enough cashflow and financial capacity to live up to our commitments without a problem," de Margerie added.

During his speech, de Margerie also reiterated that more expensive oil projects, such as extra-heavy crude, will "definitely need higher prices" than the current level. A price of $75 to $80 a barrel might be the right level, he said.

Total's CEO also emphasized the need to keep investing in research and development. R&D "cannot be cut in this time of crisis," he told delegates.

He went on to speak about renewable energy.

"Yes there is a future for solar," de Margerie said, emphasizing the need to invest in research to make it viable without subsidies. He added he doesn't expect "major progress" in that regard until around 2020.

-By Adam Mitchell, Dow Jones Newswires; +33 1 40171756; adam.mitchell@dowjones.com