Growth in Saudi Arabia's non-oil private sector slowed to a 12-month low in May as expansion of both output and new orders slackened, a survey of businesses showed on Wednesday.

However, the non-oil business activity growth in the neighbouring UAE slowed marginally as new orders expanded less rapidly, the survey added.

The seasonally adjusted SABB HSBC Saudi Arabia Purchasing Managers' Index (PMI) dropped to 57 points last month from 58.3 points in April. A reading above 50 points indicates expansion and below 50, contraction.

The data may indicate that the impact of low oil prices, which have caused some oil industry projects to be halted or scaled back, is finally feeding through into the non-oil economy, although private sector growth is still strong.

Output growth dropped to a four-month low of 63.4 points from 64.2 points, while new order growth slid to 62.7 points, its slowest since September 2011. Employment growth fell to 52.1 points, a 10-month low.

Output price inflation climbed to a six-month high of 50.7 points while input price inflation rose to 53.7 points.

The UAE PMI edged down to 56.4 points last month from 56.8 points in April. The 50-point level separates growth from contraction in the survey of 400 firms.

"The UAE's non-oil private sector continued on its robust growth trend during May," said Philip Leake, economist at data compiler Markit.

"With employment also rising solidly, the PMI looks set to remain comfortably inside growth territory over the coming months," he noted.

Output growth rose to a three-month high index reading of 62.8 points in May from 62 points in April, but the increase in new orders fell to 60.9 points from 62.1 points. Employment growth accelerated slightly.

Output prices fell for a fourth straight month, with the index at 49.7 points, while input price inflation eased to 51.6 points from 52.3 points.-Reuters