Split a file by line and have control over resulting files extension

There is a standard command for file splitting - split. For example, if I want to split a words file in several chunks of 10000 lines, I can use: split -dl 10000 words wrd It would generate several files of the form wrd.01, wrd.02 and so on. But I want to have a specific extension for those files - for example, I want to get wtd.01.txt, wrd.02.txt files. Is there a way to do it?