BP plans to withdraw its nine-day fortnight arrangement for a number of of its workforce to improve the efficiency of its customer-facing operations.

The nine-day fortnight, which was introduced to parts of the business after the acquisition of the American company Amoco in 1998, allows employees to take every other Friday off if they work a certain amount of hours during two weeks.

Employees who currently receive the benefit in the UK are based in Sunbury-on-Thames and Aberdeen. It is not known yet what proportion of the 4,000 Sunbury-based employees will be affected by the removal of the nine-day fortnight. The benefit is not provided to employees based in the firm's London corporate headquarters.

The decision to remove the perk followed a review of business practices. A spokesman for BP said the benefit was considered unsuitable for the working practices of certain employees, particularly those that work in marketing or deal with business customers.

Julie Quinn, employment partner at law firm Nabarro, questioned whether the credit crunch could be behind the move. "There is plenty of talent on the market [not] disgruntled or easily dislodged by the bonus round. Notions of family friendly policies might not have the same prominence. Obviously it is still high on the government's agenda, but I suspect the reality is we will see a sharper focus on the hard core benefits - salary and job security - and not the luxury items like [flexible] working," she said.