After falling more than $1 US a barrel early in the trading session, oil prices finished Monday with a small gain.

The price of light, sweet crude for August delivery ended the day up four cents at $69.18 US.

Oil prices initially fell following the settlement of a four-day general strike by labour unions in Nigeria.

The Nigerian unions ended their strike on Saturday after the government agreed to postpone a proposed hike in the price of fuel. The strike had paralyzed much of Nigeria's economic activity. Nigeria is the biggest oil producer in Africa and ranks among the top 10 producers in the world.

However, attention eventually swung during the trading day to focus on reports of two refinery closures. A slew of closures have investors worried about the abilities of producers to meet demand for gasoline during the summer driving season.

Also driving prices were reports that Exxon Mobil Corp. and ConocoPhillips have not reached agreements with the government of Venezuela on the privatization of that nation's oil assets. Phil Flyn, an analyst at Alaron Trading Corp., said the failure to reach an agreement sparked concerns about Venezuela's capabilty to keep up its output.