Stifel cut its earnings estimates for Tsakos Energy Navigation (TEN) but kept an optimistic tone about the tanker owner's future.

Benjamin Nolan, the investment bank's shipping analyst, reduced his earnings-per-share (EPS) estimate to $1.44 from $1.55 as a result of positioning of TEN's fleet.

The analyst said the company's aframaxes and suezmaxes earned less than he anticipated in the first quarter.

"However, the crude market remains at healthy levels and [we] would expect low oil prices to remain the overwhelming backdrop in 2016," he said in a note to clients.

Nolan,