Just three months after being ignominiously ejected from the FTSE-100, Baltimore Technologies has staged a dramatic return to the share index that should guarantee solid demand for the shares - at least for the next three months.

FTSE International, which compiles the index, will today formally announce the changes to the index. But, based on yesterday's closing prices, Baltimore will be one of five stocks to rejoin the index later this month.

The other new entrants are expected to be Granada Media, Dimension Data, Electrocomponents and Spirent.

Baltimore will be hoping that its membership of the FTSE-100 will last longer than the three-month stint it enjoyed between March and June before the slump in technology shares saw its price collapse and an inevitable exit from the index. Baltimore's share price performance has epitomised the volatility of the technology sector, where investors' attitudes can change almost instantly and where huge share price movements are by now commonplace.

As investors flocked into technology shares in the early part of the year, Baltimore soared to a high of £15 a share where the company - still a long way from reporting profits - was worth a staggering £6 billion sterling (€9.8 billion).

Within a couple of weeks of joining the FTSE-100, sentiment changed dramatically and Baltimore plummeted to a low of £3.65.

Sentiment was not helped by chief executive Mr Fran Rooney and chairman Mr Henry Beker each selling one million shares when they were trading not much off their low point.

But in the past two weeks, as sentiment shifted back, Baltimore shares have climbed more than 25 per cent.

The prospect of a return to the FTSE-100 might have seemed non-existent two weeks ago, but Baltimore's recovery in that period simply emphasises the volatility of the sector.

That volatility was even apparent yesterday, when a poorly-received set of results from software group Sema triggered a sector-wide sell-off. At one stage, Baltimore fell by almost 12 per cent to £7.97 sterling before recovering to close down just 21p on £8.79.