Mumbai, June 10: Rating agency Care Ltd has assigned a "AAA" rating to National Housing Bank`s (NHB) Rs 1,800 crore bonds programme, indicating negligible investment risk. The rating reflects the status of NHB, wholly-owned subsidiary of Reserve Bank of India, as apex financial institution for housing sector with strong asset quality, zero per cent non-performing assets and 100 per cent recovery, care said in a release here today. The strong growth prospects of the housing sector and very low default rates demonstrated by home loans over the past several years are additional comforting factors, the release said. Bureau Report