There are other manufacturers- but their variety of products are pretty limited;
Coal- Slovenia, mainly .177 and a couple .22.
Vogel, Germany, only .177 in 3 types.
Chinese company "Quan Jian" or somesuch- only Match .177 and as expensive as any of the European products.
Prospero, Estonia, only 2 pellets, both .177 and heavy, nothing apparently worth speaking about in respect to them.
Apolo- Argentina, no reviews to be found anywhere, have .177 and .22 but not a huge variety.
Daisy- pellets made in Taiwan- seem to be very good in respect to quality and accuracy for the price, but certainly not European match quality.
Air Arms- made by/where?
Gamo- Spain and China, huge variety, not found to be very accurate by most people.
Eun Jin- South Korea, heavyweight and large calibers- work very well in some guns, not so well in others.
Skenco- all alloy/plastic products, origin country unknown but Skenco is US-based. Accuracy debatable.
Crosman- all made in USA, but so many products in the lineup they are everything from "Premium" down to the lower levels of quality.
There's probably a couple others I'm forgetting...