The report said the first fruits of this venture would emerge in either 2023 of 2024, citing two unnamed people as sources.
OPPO was the fifth biggest manufacturer in terms of shipments in the third quarter of this year, according to figures from tech analyst firm Canalys, accounting for 10% of the market, behind Samsung, Apple, Xiaomi and its stablemate vivo.
Apple, Samsung, Google, Xiaomi and Huawei already design their own SoCs. But Xiaomi has yet to use an in-house designed SoC in any of its devices.
The Nikkei Asia report quoted Brady Wang, an analyst with Counterpoint Research, as saying: "If everyone is using Qualcomm's chipsets for flagship phones, then it's very hard to claim that you have unique performance and products.
"Meanwhile, you have to compete for allocations of chips and resources with your competitors during a time of shortage, and do not have direct visibility of your chip supply chain."
Huawei has been unable to manufacture any of its Kirin processors for a while, due to American sanctions. Its share of the smartphone has fallen to a fraction of what it enjoyed earlier.
Added Wang: "We still don't see very successful cases following Apple, Huawei and Samsung.
"After all, there are entry barriers, and the continuous effort of a large team is needed, as are complicated system integrations. Costs are also increasing as chip manufacturing technology advances."