His trip came as the oil ministry announced the signing of a joint venture with a British firm to set up an oil service drilling company, in the first deal of its kind.

Iraqi officials said Miliband met Prime Minister Nuri al-Maliki and Iraq′s two vice presidents, as President Jalal Talabani is abroad, before seeing Foreign Minister Hoshyar Zebari.

The talks were to focus on boosting Baghdad-London ties, trade, and on Iraq′s largely trouble-free January 31 provincial elections that were deemed a success by the international community, the Foreign Office said in London.

Last week, German Foreign Minister Frank-Walter Steinmeier was also in Iraq.

Both France and Germany were seeking business deals.

Iraqi leaders have issued an open invitation for foreign firms to return and invest in the oil-rich state, following a historic visit by French President Nicolas Sarkozy earlier this month.

On Thursday in Baghdad, the Iraq Drilling Company (IDC) and Britain-based Mesopotamia Petroleum Company (MPC) signed the accord to drill wells, oil ministry spokesman Assem Jihad said.

The new firm, called Oil Service Company (OSC), will have 90 million dollars in start-up capital and expects to drill 60 wells a month, each producing 2,000 barrels of crude per day.

"This is the first joint venture agreement signed by the oil ministry," a ministry source said. "There is not a lot of legislation in Iraq to support such a joint venture."

The source said the agreement followed two years of tough negotiations.

Miliband last visited in April 2008.

His trip comes amid a new row over British involvement in the 2003 US-led invasion.

The British government has said it would veto publication of minutes from ministerial discussions about the legality of the invasion, immediately drawing accusations of a cover-up.

British Prime Minister Gordon Brown himself visited Iraq in December and said his country′s 4,100 troops would leave by the end of July, but their mission would already be complete "by the end of May, or earlier."

British forces on January 1 handed over control of Basra airport, its main military base in the south, to Iraqi officials.

Oil-rich Basra is the country′s third largest city and considered its financial hub because of crude production and port, which gives it an outlet on the Gulf.

British troops withdrew from Basra city last September and transferred security control of the province some three months later after controlling it since the invasion.

A total of 179 British soldiers have died in Iraq since over the past six years.

Under a US-Iraqi security pact signed in November, US troops are to withdraw from towns and cities by June 30 and from the whole country by the end of 2011, although President Barack Obama is poised to accelerate the pullout.