BEIJING (Reuters) - A survey of Chinese sales managers indicates that the economy is growing but at only about half the rate of official estimates, a private survey showed on Tuesday.

China's economy has bottomed out and continues to grow at a low but stable pace, but a major pickup in growth is unlikely this year, according to the latest China Sales Manager Index (SMI) published by World Economics on Tuesday.

The SMI rose only slightly to 51.7 in July from 51.6 in June, but was a high for 2016.

As with purchasing manager indexes, readings above 50 indicate an expansion on a monthly basis, while readings below signal contraction.

July activity is slightly above the average of the last six months, World Economics said, with the consumer services sector performing better than manufacturing and heavy industry.

China on Friday reported second-quarter growth of 6.7 percent year-on-year, slightly stronger than expected and in line with the pace of expansion in the first quarter, adding to views that the economy is steadying. But official data also showed continued weakness in exports and a further slowing in investment which suggests a loss of momentum in coming months.

The SMI release did not provide any other figures apart from the headline index.

(Reporting by Elias Glenn; Editing by Kim Coghill)