New CEO takes helm at General Electric

General Electric's new CEO has taken the helm.

John Flannery officially started his new job Tuesday, succeeding Jeffrey Immelt, who served in the role for 16 years.

The 61-year-old Immelt will stay on as chairman until the end of the year when the 55-year-old Flannery, who had been president of GE's health care unit, will also assume that role.

In a letter to employees, Flannery said investors are concerned the company is underperforming and demand improvement on "cash flow, margins and cutting costs."

Immelt, in a separate missive, praised Flannery and advised employees to keep dreaming big.

Flannery takes over a conglomerate trying to reinvent itself and restore its sagging stock price. The company, which traces its roots to 1878 and inventor Thomas Edison, recently moved from Connecticut to Boston.