By Olivier Sorgho (Reuters) -French train maker Alstom reported third-quarter sales below market expectations on Wednesday, and said it was still studying the possibility of a capital increase to cut its debt pile. Alstom lost half its market value late last year after the company slashed its full-year free cash flow forecast in October, and in November said it would consider a capital increase. On Wednesday, it said it was still studying the feasibility and potential size of a capital increase. “We are relentlessly focused on the operational action plan to generate cash in the second half of …