UK's Liberty House group has trumped a bid by Tata Steel to buy bankrupt Bhushan Power and Steel, according to people directly briefed on the matter.The committee of creditors of Bhushan Power and Steel met today to open Liberty House's bid for the company after directions from the National Company Law Tribunal.Liberty House has offered an upfront payment of Rs 18500 crores to lenders of Bhushan Power and Steel against an upfront offer of RS.