The Treasury is re-looking at plans to float the Asian unit of AIG in case a bid by Prudential to buy the AIA fails, two British newspapers reported on Sunday.

Prudential boss Tidjane Thiam has been struggling to make headway with skeptical investors who question the value of his $35.5 billion acquisition of AIA.

The Sunday Times said officials had been working on the plans for two weeks, since the first signs of problems appeared with the Prudential deal -- when the UK Financial Services Authority forced a tweak in the bid and an unprecedented last-minute delay.

The newspaper said a number of Asia's biggest financial-services firms had been approached by advisers working for the American government. Chinese banks have also been sounded out on their interest.

In a separate report, the Independent on Sunday said AIG had asked Morgan Stanley and Deutsche Bank to refresh their analysis. The two were lead underwriters on the planned flotation before it was dropped in favor of the Prudential offer.

A source familiar with the situation was quoted as saying the two banks had reassured AIG they could still get a flotation away at an attractive price.

Prudential declined to comment on the reports.

(Reporting by Kate Holton; Editing by Louise Heavens)