Jawbone, the fitness wearable, is close to receiving a major investment from BlackRock, according to a report from Fortune. Sources told the financial magazine that the world’s largest asset manager was considering investing as much as $300 million.

The funding comes as reports indicated that design challenges has caused Jawbone to delay the release of the Up3 fitness-tracker bracelet that includes a heart-rate monitor. The Fortune story is here.

Re/code and the Financial Times separately said unnamed sources indicated Google was in early stages of exploring making an investment in Jawbone but Fortune said the Google talks were no longer active.