Asia Rice-Thai benchmark price falls as tender starts

* Benchmark Thai rice price falls to $550 per tonne

* Exporters only bid for small lots in Thai govt tender

* Vietnam rice falls to $450 per tonne

* Probable Philippine purchases may only have small impact (Adds quotes, comments on Vietnam, Philippines, India)

By Apornrath Phoonphongphiphat

BANGKOK, Nov 5 (Reuters) - Asian rice prices fell further on Wednesday, with top exporting countries competing to attract rare buyers as a tender by the Thai government aimed at releasing part of its stockpile added to the downward pressure.

The benchmark Thai rice price fell to $550 per tonne, barely half the record high struck in April, as the government added to supply with its 3.1 million tonne tender.

Thailand, the world's biggest exporter of the grain, wants to free up warehouses for rice it aims to buy under a price support scheme for the new crop, which is being harvested from November, but traders and industry officials said initial demand was low.

Bids had come in for only about 1 million tonnes from some 50 exporters, they said, and the government was reluctant to sell because the bids were low.