Oil cartel Opec has chosen a compromise candidate to be its next secretary general, as it seeks to heal internal rifts and check increasing indiscipline among its members.

Opec members gathering in Vienna elected Alvaro Silva Calderon, the current Energy Minister in Venezuela, to the job on Wednesday.

The move represents a neat transition from the incumbent, Ali Rodriguez, a previous Venezuelan energy minister, who is returning home to take up his old job.

More conveniently for Opec, the choice of a Venezuelan candidate helps calm a potential squabble over the post between Saudi Arabia and Iran, the cartel's two biggest producers.

With Venezuela currently in trouble for reportedly exceeding its agreed oil production quotas, it could also help rein in Opec's third-biggest member.

New faces

The selection of a successor to Mr Rodriguez was the main piece of business in what otherwise seems an uneventful Opec meeting.

Mr Rodriguez wanted to make his mark...

With oil prices steady at around $25 per barrel, slap-bang in the middle of Opec's target range, there has been no pressure for changes in output.

More troubling, however, is the growing fear that certain countries could be quietly producing more than they admit to - an ever-present danger in any cartel arrangement.

Venezuela, whose obedience to Opec policy has see-sawed dramatically in recent years, is now seen as one of the worst offenders.

According to unofficial estimates, Venezuela is producing roughly 5% more than it promised to Opec.

No fireworks

The selection of Mr Silva, which had been widely anticipated, eliminates the need to choose between Iran and Saudi Arabia, Opec's leading powers.

... while Mr Silva prefers to leave things alone

Reluctance to allow influence to swing too far in either direction has meant that the cartel's top officials tend to be from medium-sized producers.

Mr Silva is unlikely to provide any great fireworks, however.

Mr Rodriguez was credited with transforming a normally routine job into a true leadership role, rebuilding some of the prestige that Opec lost in the 1990s.

But Mr Silva is seen as a quiet, undemonstrative character.

At 73, he is said to be taking the Opec job as a prelude to retirement, rather than as a means to make his mark.