The outlook for Africa-focused Tullow Oil is negative, though the company may recover on the back of new Ghanaian operations, Moody's Investors Service said.

Moody's said the outlook on "all Tullow's ratings is negative," though it confirmed its position on the Africa-based explorer.

Tullow last month reported that revenues were down 27 percent for the year. Net debt rose to $4 billion for the year, compared with $3.1 billion for the previous year. Losses narrowed, however, from year-end $197 billion from 2014 to $1.09 billion last year.

Moody's in its note said Tullow may recover on the back of the planned mid-2016 start up of its Tweneboa Enyenra Ntomme, or TEN field, off the coast of Ghana. The company said the first batch of produced oil is expected this summer. At its peak, the TEN field should be able to produce up to 80,000 barrels of oil per day.

"A planned reduction in capital spending post first oil from the TEN development should allow Tullow to return to positive free cash flow generation in 2017," Moody's said.

In December, Tullow, which has headquarters in London, sent its full development plans to the Ghanaian government for the offshore Jubilee field, which could help drive the production figures for this year.

Tullow Chief Executive Aidan Heavey in January said financial maneuvering last year left it with "financial headroom" of $1.9 billion to start 2016.