(Adds details of the investment) Feb 10 (Reuters) - Pacific Biosciences of California Inc said on Wednesday SoftBank Group Corp will invest $900 million in the gene sequencing firm, sending its shares up 21% before the bell. The latest healthcare investment from SoftBank, in the form of convertible debt, will help accelerate the commercialization of Pacific Biosciences’ gene sequencing technology. Last month, Bloomberg News reported that SoftBank had picked up a 6% stake in the company. Pacific Biosciences’ stock has risen more than nine-fold in the last 12 months and has a market value of $7.4 billion. Menlo Park, California-based Pacific Biosciences, which went public in October 2010, develops and manufactures DNA-sequencing systems used for research and treatments. Its technology can decode extensive stretches of DNA with a high degree of accuracy. SB Management, a unit of SoftBank Group Corp, will make the investment in convertible senior notes, which will have an initial conversion price of $43.50 per share of Pacific Biosciences. In January 2020, Illumina Inc scrapped a $1.2 bln merger with Pacific Biosciences, following an antitrust complaint that said the deal was meant to prevent the gene sequencing company from developing into a competitor.