India's Tata group is searching for a way to keep alive its hopes of regaining control of Air India, the national carrier it founded but lost when it was nationalised in the 50s.

Since its partner, Singapore Airlines (SIA), backed out over the weekend, Tata is now the only remaining bidder in Air India's privatisation.

The group said on Monday it was keeping all options open, including bidding on its own.

"We are assessing the situation with an open mind," a spokesperson told Reuters.

"It is less than two days since Singapore Airlines pulled out, and it is too early to say which way we will go," he added.

Possible partners

Speculation over Tata's next move centres on Delta Airlines of the US and Air France who had considered a joint bid but did not lodge an offer by the deadline.

Another partner could be Europe's second largest airline Lufthansa, a subsidiary of which submitted a bid with the Hinduja brothers that was withdrawn last week.

Tata declined to comment on the reports.

Singapore Airlines (SIA) said on the weekend that strong political opposition from "sections of political groups, trade unions and the media" to the privatisation was the reason why it had pull-out.

The sale of the Air India is considered a test of the government's commitment to its ambitious privatisation programme, which is scheduled but unlikely to be completed by the year end.

India has singled out 27 state-run companies for sale with the hope of raising 120bn rupees ($2.55bn).