BRUSSELS, Belgium (Sept. 11)—Solutia Inc. plans to sell its 50-percent share in Advanced Elastomer Systems L.P. "We are as surprised as anyone about this announcement," said a spokeswoman for ExxonMobil Corp., which owns the remaining 50-percent share in AES. ExxonMobil Corp. has right of first refusal on Solutia´s share in AES, she said. St. Louis-based Solutia is seeking to focus on its core polyamide business and to generate capital to pay down debt. While admitting surprise at Solutia´s plans, an executive at AES´s Brussels headquarters said Solutia had different strategic interests to Exxon, particularly in term of supplying raw materials to AES. "Solutia has been very happy with our performance over the whole existence of AES. We are a very big asset to them and are a very saleable company," said Ulf Nilsson, business director, consumer markets.