The forum, which marks its 10th anniversary this year, was to be attended by top Kremlin speakers, including a senior presidential economic adviser, Arkady Dvorkovich, and Deputy Economic Development and Trade Minister Kirill Androsov.
Business leaders who had pulled out at the last minute included Sergei Bogdanchkov, president of the state-controlled oil company Rosneft [RTS: ROSN], and Alexander Medvedev, head of energy giant Gazprom's [RTS: GAZP] export arm.
Russian and foreign media have said the partial boycott was ordered by the Kremlin as punishment for Britain's reluctance to respond to the London-based oligarch Boris Berezovsky's appeals for the overthrow of Vladimir Putin's government.
The Financial Times also said Monday the boycott highlighted the difficulties of doing business in Russia.
"The conference pullout highlights the challenges of doing business with Russia," the business daily said. "While the economy is booming, creating opportunities for many companies, the Kremlin is increasingly ready to intervene in the economy, even, it seems, in the conference sector."
The paper further cited Royal Dutch Shell's experience in Russia. The oil giant was recently pressed to sell control in the vast hydrocarbon project off Russia's Pacific Coast, Sakhalin II, to Gazprom.
The Kremlin has said its move to regain control of "strategic" sectors is designed to restore order in the country after the arbitrary privatization deals and economic turmoil of the 1990s.
On Monday, the forum will be addressed by European Bank for Reconstruction and Development (EBRD) President Jean Lemierre, Shell Russia President Chris Finlayson, Alcoa aluminum giant Chairman and CEO Alain Belda, Barclays Capital Chairman Hans-Joerg Rudloff and other business leaders.
From Russia, Rustam Minnikhanov, prime minister of the oil-rich Russian republic of Tatarstan, and lawmaker Alexander Lebedev will speak at the forum Monday.
This year, the forum will assess Russia's development in the last 10 years. Other problems to be raised include stock market challenges facing Russia, Russian energy companies' ambitions on world markets, investment in the country and other sensitive issues.
The Russian business daily Kommersant suggested earlier the order for top Russian speakers to stay away from the London forum could also have been in response to criticism by European bodies of Moscow's handling of the March of Dissent earlier in April.
Rights groups, the opposition and journalists have accused police of abusing their authority and violating the law during the dispersal of the unsanctioned rally in Moscow and St. Petersburg, which demanded the president's resignation.
Official reports said police detained 250 and 170 people in the two cities, respectively. And The European Parliament said it would stay in close touch with the Russian opposition and would follow developments in Russia.
