The frayed nerves of investors in the telecoms sector will be further tested next week as Vodafone and Orange update subscriber numbers. Quarterly figures from a mixture of blue-chips should add to an interesting week.

Chip designer Arm Holdings' final results on Monday should show strong year-on-year growth and an improvement on a quarter-to-quarter basis.

Full-year pre-tax profits are expected to be about £50m - up 41 per cent on last year - while quarterly profits are forecast to move ahead five per cent on the previous three months at £13.5m.

Higher income from the licence fees charged by Arm to customers should offset weaker royalties as the markets for mobile phone handsets and networking equipment weaken.

Two of Britain's biggest mobile phone operators will give a guide to the current balance of power in the sector on Tuesday when Vodafone and Orange issue revenue and subscriber numbers for the fourth quarter.

Growth in user numbers for both companies will slow in the face of a saturated market, while average revenue per user figures will be slightly lower owing to seasonal factors and poorer roaming revenues after September 11.

Telecom services provider Kingston Communications issues third quarter figures on Tuesday but will need to demonstrate progress in revenues and underlying profits if it is to sustain investor confidence in a fragile sector.

Mortgage bank Northern Rock is expected to report a solid performance when it reports on Wednesday.

While business confidence, corporate earnings and equity markets had a shaky 2001, house prices enjoyed a bumper year and provided Northern with a 17 per cent surge in full-year pre-tax profits at £293m. Fund manager Gerrard said the firm maintained the lowest cost base of any European bank and was able to price aggressively and capture market share.

l Companies reporting results next week include:

MONDAY - Finals: Arm Holdings, Fairbriar. Interims: Sportingbet (Q3).

TUESDAY - Finals: Aukett Group, Cosalt. Interims: Dataflex Holdings, Games Workshop Group.

WEDNESDAY - Finals: IFX Power, Northern Rock, Parthus Technologies, Partridge Fine Arts.

THURSDAY - Finals: Arthur Shaw & Co, AstraZeneca, Crest Nicholson, Fitness First. Interims: Fairplace Consulting, Scottish Power (Q3), Wolseley.