Companion novels tend to use the same characters but have completely unrelated plots. Sequels tend to carry the story from one to another.
There will definitely be a sequel to the novel-Ghost Knight by Cornelia Funke.
No. There was never a sequel novel to The NeverEnding Story. There was a movie sequel but it was not written by Ende.
The sequel, 'Tis, was only offered in novel form.
As of March 2014, no sequel was published or planned for the novel.
No, there is no sequel to Storm Thief.
Vanish:A Firelight Novel
There will be a 'companion novel' set in the Moonlit Lands, based on a different fairytale. Whether it will feature characters from the original book is not known. This book will probably be released in 2015 or 16, according to the author's blog and website.
No, there is no direct sequel to "The Light in the Forest" by Conrad Richter. The book is a standalone novel set in the 18th century about a boy caught between two cultures, the Native American and the European.
omoo .... Herman Melville's sequel to Typee
Gump and Co is the sequel for Forrest Gump. It was written as a response to the film, rather than as a companion to his original novel. It picks up after the movie ends, and follows Forrest through the 1980's and 1990's.
No, there is no sequel to "Halo" by Zizou Corder. The book is a standalone novel and does not have any direct sequels.
No, there is no sequel to Eyes of the Dragon, but it is connected to the Dark Tower series.