Toyota unveiled at the Geneva Motor Show its Yaris HSD concept, which represents the first down-sizing of Toyota's Hybrid Synergy Drive® technology. Reuters

Toyota motors will upgrade engine assembly lines worldwide to cut output cost and make even the smaller assembling units profitable, the Nikkei reported.

Toyota has spent about 20-30 billion yen on current assembly lines with production capacity of at least 200,000 units till date, the report said, adding that the new assembly lines that have a production capacity of 100,000 units may have apparently come up at an investment of 10-15 billion yen.

The automaker is reportedly planning to double its hybrid offerings by launching 11 models in Japan by the end of 2012.

By the end of the year, some of the lines at the auto giant's Shimoyama plant will be upgraded and brought on stream, according to the daily.

In China, India and Brazil, deploying conventional assembly lines that require massive investments have become a major issue as it increases fixed costs for lifting production capacity.