By Sarah Rainsford BBC correspondent in Moscow

Mikhail Fradkov is currently Russia's ambassador to the European Union. Before that he headed the country's tax police. Earlier still, he was Minister of Trade and Deputy Secretary of the Security Council.

Fradkov (left) has Putin's trust

Announcing his choice, Mr Putin described Mikhail Fradkov, 53, as a man with wide-ranging experience from fighting corruption as head of the tax police, to representing Russia abroad.

Mr Fradkov's surprise nomination has ended six days of feverish speculation, in which dozens of names were put-forward as potential prime ministers. The low-profile EU envoy was never among them.

Echo of Moscow radio station ran a competition at the weekend - offering prizes to anyone who could predict Mr Putin's choice correctly.

The main rumours swirled around Sergei Ivanov, acting Defence Minister and the man many predict will succeed Mr Putin as president.

He looks like a fairly loyal administrator whose primary function is to follow the word of the Kremlin Roland Nash Chief strategist, Renaissance Capital

Others put their money on acting Finance Minister Alexei Kudrin.

And there were mounting whispers about several figures from high-up in the presidential administration.

Following Mr Putin's announcement, the prizes at the radio station have presumably been put back on the shelf.

Last week, the president explained his decision to dismiss the government with a desire to hit the ground running with reforms following next month's presidential elections. He repeated that line as he announced Mr Fradkov's nomination.

"I want you to work with Mikhail Fradkov to finish the reforms that have dragged on for so long," Mr Putin told ministers. "I want them completed in the shortest possible time."

Dismissing Kasyanov (left) was Putin's first February surprise

According to the constitution, parliament has one week to consider the president's choice. But it is highly unlikely to stand in his way.

Speaker of Parliament Boris Gryzlov immediately hailed Mikhail Fradkov as an honest and fair professional.

"The various factions in the Duma have plenty of time to put questions to Mikhail Fradkov and form their own opinion," Mr Gryzlov told Russian media. "But the opinion of United Russia is that we will support his candidacy."

Mr Gryzlov announced that parliament, or the Duma, would formally consider the president's choice on Friday.

With a huge pro-Putin majority in the chamber a vote of approval is all but guaranteed.

Second shock

Analysts and political commentators alike were taken aback by the second shock announcement from Mr Putin in a week. But the financial markets absorbed the news calmly.

There had been fears Mr Putin would nominate a Kremlin hawk: possibly a former FSB official in favour of more aggressive intervention in the economy.

Instead, many analysts described Mikhail Fradkov as a neutral figure with little political personality of his own.

"He looks like a fairly loyal administrator whose primary function is to follow the word of the Kremlin," said Roland Nash, chief strategist with Renaissance Capital in Moscow.

'Moderate liberal'

Alexei Volin, a former member of the presidential administration, expressed some concern that the president's nominee is such a political unknown. But like Mr Putin, he stressed Mikhail Fradkov's experience in foreign trade and economics as a bonus.

Others pointed-out that the EU envoy appeared free of any binding ties to a particular power-group, or political clan. They described him as a moderate liberal and as a reasonably acceptable figure for investors.

But most Kremlin-watchers characterise Mikhail Fradkov as a civil servant above all.