UPDATE 1-Centrica's British Gas raises prices by 6 percent

* Domestic gas and electricity prices to rise 6 pct on Nov16

* Average annual fuel bills will increase by around 80pounds

* British Gas says faces rising wholesale prices and upgradecosts

(Adds detail, quote, share price)

LONDON, Oct 12 (Reuters) - Centrica PLC , the ownerof British Gas, Britain's biggest energy supplier, is hiking itsdomestic gas and electricity prices by 6 percent next month,saying the "unwelcome news" for already tight household budgetswas necessary to cover rising wholesale prices.

Annual dual fuel bills for British Gas customers willincrease on average by around 80 pounds following the Nov. 16rises, Centrica said in a statement on Friday.

The company said it was facing rising wholesale energyprices against a backdrop of dwindling North Sea gas supplies,as well as higher costs to upgrade the national grid and make itmore energy-efficient.

"We know that household budgets are under pressure and this1.50 pound per week rise will be unwelcome, said British GasManaging Director Phil Bentley.

"However, we simply cannot ignore the rising costs that arelargely outside our control, but which make up most of thebill."

British Gas said it was increasing the help available tocustomers to reduce their energy consumption, for example inimproving their home's insulation.

"We need an energy efficiency culture in Britain today;rising prices don't have to mean rising bills. We are offering ahuge amount of help to customers to help them cut the amount ofenergy they use and keep their bills under control," it said.

Shares in Centrica were down 0.7 percent in morning trading.

(Reporting by Natalie Huet; Editing by Paul Sandle)

((natalie.huet@thomsonreuters.com)(+44)(0)(207 5421272)(Reuters Messaging:natalie.huet.thomsonreuters.com@reuters.net))