OSLO (Reuters) - Offshore services provider Subsea 7 cut its 2019 revenue outlook on Thursday but predicted a rebound next year as demand for oilfield services and from renewable energy providers is set to increase, boosting its shares almost 6%.Subsea 7 now expects a slight decline in revenue this year from 2018, while it had previously expected it to remain unchanged. It maintained a forecast for a drop in earnings before interest, tax, depreciation and amortisation (EBITDA)."2019 is expected..