LONDON, Sept 28 (Reuters) - Catalan bond yields jumped more than 20 basis points on Monday after separatists won a clear majority in Catalonia's parliament in an election that sets the region on a collision course with Madrid over independence.

Spain's constitution does not allow any region to break away, so the prospect of independence remains highly hypothetical.

Ten-year Catalan yields were indicated at 4.23 percent early on Monday, up from 3.99 percent on Friday.

Spanish yields were steady at 2.03 percent.

(Reporting by Marius Zaharia; Editing by Jemima Kelly)