WASHINGTON (Reuters) - President Barack Obama will nominate the head of a doctors group that promotes his signature healthcare law to be the next U.S. surgeon general, the White House said on Thursday, shortly after Obama proposed a "fix" for the latest problem with the law.

Vivek Hallegere Murthy, president of Doctors for America, will succeed Rear Admiral Boris Lushniak, who has been acting as the surgeon general since July, overseeing public health endeavors around the country, after Regina Benjamin completed her four-year term.

Doctors for America is a group of 15,000 physicians and medical students that has rallied behind Obamacare through participating in marches, filing an amicus brief in the Supreme Court case on the law, and even visiting the Republican National Convention to promote it, according to the group's website.

In 2011 Obama appointed Murthy to an advisory group on prevention formed under the law, the White House said.

On Thursday, the president tried to address a rash of cancellations of health insurance policies that do not meet Obamacare's standards by allowing those policies to continue well into 2015.

The solution could create new snags. Insurers and state regulators said it may lead to higher premiums and logistical nightmares.

Murthy, who received his doctor of medicine and his master of business administration degrees from Yale University and completed undergraduate studies at Harvard University, is an attending physician and instructor at Brigham and Women's Hospital at Harvard.

He also helped found two technology companies related to medicine: Trial Networks, a cloud-based platform for pharmaceutical and biotechnology trials; and Epernicus LLC, a networking site for research scientists, according to his LinkedIn profile and the company websites.

(Reporting By Lisa Lambert; Editing by Mohammad Zargham)