Oil giant BP says its latest procedure to plug the leak in a ruptured oil well in the Gulf of Mexico was successful.

The company issued a statement early Wednesday, a day after it began the so-called "static kill" operation. The operation involves pumping heavy mud into the well, and eventually sealing it permanently with cement.

BP said after eight hours of pumping mud into the well, the mud is controlling pressure inside the well -- a state BP said was the desired outcome. It said pumping has stopped and experts are monitoring the well to see whether more mud is needed.

The company said it will work with the government's oil response chief, retired Coast Guard Admiral Thad Allen, to decide whether to follow up the mud with an injection of cement through the same route.

Authorities have said 4.9 million barrels of oil leaked from the well after it ruptured April 20, in a rig explosion that killed 11 people.

A temporary cap stopped the leak when it was installed in mid-July.

But officials said not all of this oil flowed into the Gulf.  They said containment activities conducted by BP under U.S. government direction captured approximately 800,000 barrels of oil prior to the capping.

The leak has caused environmental and economic damage in the Gulf, angering and creating hardship for people who rely on the waters for their livelihoods.

BP is facing about $30 billion in cleanup costs.  The company says it will sell its Colombian business to a consortium of Ecopetrol, Colombia's national oil company, and the Canadian company Talisman for $1.9 billion.