TRADING in Northumbrian Water shares begins in earnest this morning as the company makes its long-awaited return to the big stage and full listing on the London Stock Exchange.

The firm rejoins the premier league of British companies following an eight-year absence - and is likely to be welcomed with open arms by the City's big guns.

Since May, when the company was bought from French utilities firm Suez, the business, based in Durham, has been listed on the smaller Alternative Investment Market (Aim) and has seen share prices rise from an initial flotation price of 100p to about 110p.

Today's listing makes Northumbrian shares available to the biggest players in the market and analysts think demand from the City's institutional investors and pension funds may push the price even higher.

Senior managers at Northumbrian Water were buoyant ahead of this morning's listing.

When the firm announced at the end of last week the date for full listing, managing director John Cuthbert declared it "a significant day in our corporate history" .

He said: "When we floated on Aim in May, we indicated that this move to the official list would happen as soon as reasonably practicable, and I am pleased that we have been able to complete the process so swiftly.

"We look forward to life on the official list and continuing to deliver value for both our customers and shareholders."

Today's move comes at the end of a turbulent decade for Northumbrian Water.

Privatised in 1989, Northumbrian Water took over several of its smaller North-East rivals during its early years in the 1990s and acquired interests in the South of England, streamlining its management operation along the way.

In 1995, Northumbrian Water was swallowed up by French-owned Lyonnaise des Eaux and subsequently Suez.

But the debt-laden Suez was forced to off-load its prized asset earlier this year, although the French company will keep a 25 per cent stake.

Northumbrian Water shares are expected to prove particularly attractive to a stock market which has also suffered a turbulent few years - offering a safe bet for investors hoping for a long-term dividend return from the utilities, rather than the high-risk of technology stocks for example.

Director of finance Chris Green said: "It is good for investors - it is a safe haven which offers a good return and stability for their investment."