More than four months after becoming Jharkhand chief minister, Jharkhand Mukti Morch supremo Shibu Soren was on Thursday defeated in an assembly bypoll plunging the state's ruling UPA into a crisis and threatening his continuance at the helm even as he tried to delay his resignation.

Soren was defeated by Gopal Krishna Patar, a candidate of Jharkhand Party -- a constituent of UPA -- by a margin of 9,062 votes in the bypoll to Tamar constituency held on January three last, the counting for which was taken up on Thursday.

The JMM supremo sought to delay his resignation as chief minister by saying, "I will go to Delhi [Images] on Thursday or Friday and meet the UPA leadership, including Rashtriya Janata Dal chief Lalu Prasad, there before taking any decision."

"I will also meet state UPA chairman Madhu Koda, and other allies and seek their suggestions before taking a decision," Soren added.

UPA sources said Soren is expected to leave for Delhi soon to discuss the situation with the central leadership.

Deputy Chief Minister Sudhir Mahto said in Jamshedpur that the UPA government would continue in Jharkhand despite the defeat of Soren.

"We will try to make alternative arrangements to continue with the UPA dispensation in the state," he said, adding that UPA constituents will sit together soon and discuss the issue.

The chief minister's defeat by Patar was preceded by turmoil within his government barely a fortnight before the bye-election when Soren sacked Jharkhand Party leader Enos Ekka for refusing to withdraw his party's nominee in Tomar.

Asked whether any UPA ally had worked against him during the bypoll, Soren said he had believed every ally during the contest.

This is Soren's second stint as Jharkhand chief minister after a nine-day tenure in March 2005 when he had to quit even before proving majority in the assembly.

Soren became chief minister after his party withdrew support to the Madhu Koda-led UPA government on August 17 last forcing Koda to resign. This paved the way for Soren to head the government for the second time.

Meanwhile, Madhu Koda hinted that he was not averse to taking over the mantle if the central UPA leadership decided to change guard in the wake of the Soren's defeat.

"I have always been adhering to the UPA directives. Whatever the leadership will say I am ready to follow it," Koda told media persons when asked whether he aspired for the post again.

"The chief minister might have lost the seat but the UPA is still in power and will not leave the turf," Koda said.

BJP's state unit president, P N Singh, said Soren should quit.

"It is the defeat of the entire UPA and Congress should take responsibility for this," Singh said.