My dictionary says that けいえい 【経営】 is pronounced in one syllable with one really long vowel.
Having lived all of my life in Japan as a native speaker, I have never heard the word 「経営」 pronounced that way.
In most cases (like over 99% of the time), it is pronounced:
in two elongated syllables.
Once in a while (the remaining less than 1 %) when a person needs/wants to emphatically pronounce it for some specific reason, that person might pronounce it:
in four exaggerated syllables.
Again, I do not even know how 「経営」 could possibly be pronounced in one syllable. In addition, even if such pronunciation were possible (like 「けーーー」?), almost no one would understand what word it would be if pronounced that way.