KIEV - Ukraine's Viktor Yanukovich was sworn in as president on Thursday, pledging to balance his country between Russia and Europe and win back foreign support for the struggling economy.

Yanukovich promised to fight corruption and poverty and restore political stability as he took the oath of office. The low-key ceremony reflected a bitterly fought election that is still disputed by his rival, Prime Minister Yulia Tymoshenko.

His inauguration marked a comeback from humiliation in 2004 when mass protests, known as the Orange Revolution, overturned an election that had been rigged in his favour.

Yanukovich is expected to improve relations with Russia, Ukraine's former Soviet master, after five years of estrangement under his pro-Western predecessor Viktor Yushchenko.

In Thursday's speech he kept his options open, declaring he saw Ukraine as a bridge between East and West, an integral part of Europe and of the former Soviet Union at the same time ... a European non-aligned state.

A top aide later confirmed that he would travel to Brussels, headquarters of the European Union, on March 1 and visit Moscow on March 5.

Speaking to a gathering of officials, lawmakers and foreign dignitaries after accepting the traditional trappings of office, the 59-year-old Yanukovich said the country faced colossal debts, poverty, corruption and economic collapse.

Ukraine needs a strategy of innovative movement forward and such a strategy has been worked out by our team, he said.

Turning to the paucity of foreign investment in the ex-Soviet republic of 46 million, he said he sought to restore political stability, end corruption and set out rules governing links between the state and business.

These were all necessary conditions for investors and international financial institutions to establish trust in Ukraine, he said.

Yanukovich's triumph may be short-lived unless he can bring an unreliable parliament under his control and quickly rid himself of a prime minister who is actively opposed to him.

His powers as president are limited to foreign and defence policy and some other functions, and he badly needs a prime minister whom he trusts to run the economy or he will find himself unable to keep the promises he has made, like Yushchenko before him.

Ukraine's economy has been hit hard by the global downturn which hurt its vital exports of steel and chemicals and halved the hryvnia's value to the dollar over the past 18 months.

The country is dependent on a $16.4 billion International Monetary Fund bailout programme, but lending was suspended late last year and is only likely to resume when stability returns.

The finance ministry said an IMF technical mission would visit on April 7. This usually leads to a full-blown visit from IMF officials who may later decide to restart the programme.

A burly former mechanic backed by wealthy industrialists, Yanukovich had a deprived childhood in eastern Ukraine and as a young man was convicted twice for petty crime including assault.

He has hinted at possible concessions to Moscow over the future of Russia's Black Sea fleet, based in Ukraine's Crimean peninsula, and has proposed the creation of a consortium including Russia to run the country's gas pipelines.
However, he says he wants to change a 10-year-old agreement on supplies of Russian gas to Ukraine.

Yanukovich beat Tymoshenko by 3.5 percentage points but won the support of only a third of the 37 million-strong electorate.

The voting pattern highlighted a sharp split between Russian speakers in the industrial east and south who backed him, and Ukrainian-speakers in the west and centre voting for Tymoshenko.

Tymoshenko dropped a legal challenge to the vote last Saturday but still maintains he is not legitimately elected. She and most of her parliamentary bloc stayed away on Thursday.

She is resisting attempts to oust her as prime minister, signalling continued political tension at least in the short-term. Yanukovich and his powerful backers want to draw deputies away from her coalition and forge a new one.

Forging a coalition requires horse-trading and as long as Tymoshenko's survives, Yanukovich may find it difficult to get the majority he needs to carry out key duties such as appointing foreign and defence ministers and a new central bank head.

(Additional reporting by Sabina Zawadzki, Yuri Kulikov and Pavel Polityuk; Editing by Mark Trevelyan)