HI-TECH firm Bookham Technology has joined the FTSE 100 listing of top UK companies, writes Maggie Hartford.

The company, which makes components for the switches and circuits controlling optical signals used for Internet traffic, was the only technology firm to join the list of the 100 companies with the highest value on the London Stock Exchange.

Many of the Internet companies which joined last quarter were ousted after their market value plummeted.

Bookham, based at Milton Park, near Abingdon, which is a finalist in the Oxfordshire Business of the Year Awards, joined at number 72, with a market capitalisation of 4.52bn.

The company, which floated in March, was founded by engineer and businessman Dr Andrew Rickman,whose holding is worth 1.3bn.

He said: "It's obviously exciting for us and I am pleased about the recognition it confers on the company."

His breakthrough was to use silicon, a cheaper material with proven manufacturing methods.

Dr Rickman, who received an OBE this week from the Queen, set up the company in 1989 with four people at the Rutherford Appleton Laboratory, Chilton.

Bookham now makes 10,000 chips a month and plans to double production by the end of the year, creating 180 jobs at a new factory being built in Swindon. Its workforce at Milton Park has increased from 225 to almost 400 since January. The new factories are due to start operating this month.

Psion, the hand-held computer group with its industrial manufacturing centre at Milton Park, lost its place in the FTSE 100, falling to 114.

Building materials company Hanson, which employs several hundred people in Oxfordshire, returned to the index.