Complex sentence: In June 2006 Yvert et Tellier published a new catalog of French stamps, a cheaper pocketbook version containing just pictures and prices, as did Cérès, the second main philatelic publishing company in France.
Split into simpler sentences: In June 2006 Yvert et Tellier published a new catalog of French stamps, a cheaper pocketbook version with just pictures and prices. At the same time, so did Cérès, the second main philatelic publishing company in France.