Firms paid a record £18.8 billion in dividends over the first three months of 2012, a jump of 25% on a year earlier.
But rather than highlighting a shareholder bonanza, the latest Dividend Monitor from Capita Registrars said special payments of £2.2 billion by Vodafone and Cairn Energy masked a weaker than expected performance.
Adjusting for the one-off factors, underlying growth was 6.6% higher than a year ago in the first quarter, much slower than the 12.8% increase in 2011 and below Capita's forecast growth rate for this year.
The FTSE 250 Index showed the most weakness as payouts by firms in the second tier of the London stock market fell 9% year-on-year to £915 million, the first quarterly decline since 2009.
Cable & Wireless Worldwide slashed its payout - costing £24 million - and there has been more general caution among mid cap stocks about paying dividends.
Capita Registrars chief executive Charles Cryer said the year will still be a record one for dividend growth.
He added: "We have upgraded our headline forecast to reflect the big one-offs, but the picture is more complex than the headlines suggest.
"The economy stumbled in the fourth quarter as the eurozone crisis knocked confidence in Britain and raised fears of a new credit crunch.
"Roughly two-thirds of firms who paid in the first quarter decided their dividends before the new year - the fourth quarter economic weakness seems to have caused them to show greater caution."