SAN FRANCISCO — Facebook said on Thursday that it would end an experiment in six countries that separated posts from news sites and publishers from other material on the social network.

News organizations in the countries — Slovakia, Sri Lanka, Cambodia, Bolivia, Guatemala and Serbia — had said they were blindsided by the Facebook experiment when it began in October and complained that it had led to a surprising rise in misinformation.

Facebook stopped short of acknowledging that the changes made in the experiment, called Explore, contributed to that increase in misinformation, but the company said it could have done a better job communicating with publishers about what was happening.

“In surveys, people told us they were less satisfied with the posts they were seeing, and having two separate feeds didn’t actually help them connect more with friends and family,” Adam Mosseri, who heads Facebook’s News Feed, said in a statement posted online. “We also received feedback that we made it harder for people in the test countries to access important information, and that we didn’t communicate the test clearly.”