Shares in the group fell 14.5p to 458.5p against a soaring stock market as Shell revealed a 10 per cent drop in net income between April and June to pounds 1.07bn. It left earnings for the first half of the year down 15 per cent to pounds 2.49bn.
Mark Moody-Stuart, Shell's group managing director, said share buybacks had been considered often but were "just a non-starter" because of a 25 per cent tax charge for investors in the Netherlands.
BP this week announced plans to buy back shares next year to raise its debt levels. Shell, in contrast, has pounds 7bn of cash in the bank.
Hinting at the possibility of a generous interim dividend increase in September, Mr Moody-Stuart said: "I haven't heard shareholders complaining lately. Shell is a huge cash-generating machine."
Shell blamed the profits drop partly on the increase in the value of sterling, which knocked pounds 117m off second-quarter earnings. Another pounds 30m was wiped from chemicals profits after what the group described as "not terribly good planning" saw almost three quarters of the division's maintenance budget spent in just three months. It left chemicals profits outside the US down by 38 per cent in the second quarter to pounds 86m.
In a clear indication yesterday of Shell's drive to inject a more entrepreneurial culture into the organisation, Mr Moody-Stuart revealed that the group was unlikely to meet this year's pounds 8bn investment target. Just 38 per cent of the annual budget was spent by the middle of this year, suggesting divisional managers were paying greater attention to profits.
Shell's rate of return on capital fell in the first half of the year from 11.8 per cent to 11.5 per cent, compared with a modest internal target of 12 per cent and BP's surprise surge in returns to 19 per cent earlier this week.
Fergus McCleod, oil analyst with NatWest Securities, welcomed the investment slowdown. "It's virtually impossible now for them to spend their full investment budget for this year. This is a hopeful sign that efficiencies will come through to the bottom line faster than expected."