ABJ Sep 7 - U.S. President Barack Obama is set to propose that companies be allowed to more quickly write off 100 per cent of new investments in plants and equipment through 2011.

The proposal tops a list of other announcements, from a proposed expansion of the research and experimentation tax credit to $50 billion in additional spending on roads, railways and runways.

Companies will be able to deduct new investment expenses, but over a longer period of time, from three to 20 years. The proposed change, which would let companies keep more cash now, is meant to give to those who may be hesitant to invest an incentive to expand, spurring a currently stalled American economy.