Ericsson has landed its largest managed services contract in China to date with China Mobile Hebei, a regional subsidiary of China Mobile that has 35 million subscribers.

Under the terms of the three-year deal, Ericsson will handle field maintenance for all of China Mobile Hebei’s 22,000 GSM/TD-SCDMA base station sites. Financial conditions of the deal were not disclosed.

Mats Olsson, president of Ericsson China and North East Asia, said in a statement that the contract showed China Mobile Hebei’s trust in Ericsson’s managed services business. China Mobile Hebei is one of Ericsson’s most important customers and strategic partners, Ericsson said. The two companies have been working together for more than 23 years.

The cooperation between China Mobile Hebei and Ericsson gained support from the government of Hebei Province, which said it hopes Ericsson will use the contract to set a benchmark for field maintenance services in China.

China Mobile is the largest operator in the Hebei province, which has a population of 70 million and its area is almost the size of the U.K. Country-wide, China Mobile has more than 500 million subscribers.