(ShareCast News) - Intel will start making smartphone chips in one its factories based on designs by London-listed ARM Holdings.The two companies said they expected the agreement will be "mutually beneficial", which may come as a surprise to many who often perceive Intel and ARM as being rivals.Intel's x86 chip architecture is leading the PC sector while ARM-based chips are used in a majority of phones and tablets."[I] am wowed by moments of cooperation that redefine the industry landscape," Will Abbey, an executive at ARM, said in a blog."This agreement is one example of that and will deliver immense value to the design ecosystem and ultimately to our partners."LG will be the first client to take advantage of the partnership.Intel has incorporated some of ARM's technologies in the past but the latest development marks another step-up in their relationship.The US company said the smartphone chips will combine its ability to make its high performance 10-nanometre transistors with ARM's most advanced designs.